ECS - UNIT - 4.docx

UNIT - 4 Basics of Computer Networking Computer Networking is the practice of connecting computers together to enable communication and data exchange between them. Basic Computer Network Topics Explained Visually Basics building blocks of a Computer network are Nodes and Links. Network Node --...

UNIT - 4 Basics of Computer Networking Computer Networking is the practice of connecting computers together to enable communication and data exchange between them. Basic Computer Network Topics Explained Visually Basics building blocks of a Computer network are Nodes and Links. Network Node -- Computer, Phone , Tablet , Modem, Router, etc., Link - wires or cables or free space of wireless networks.  Network: A network is a collection of computers and devices that are connected together to enable communication and data exchange. Nodes: Nodes are devices that are connected to a network. These can include computers, Servers, Printers, Routers, Switches, and other devices. Service Provider Networks: These types of Networks give permission to take Network Capacity and Functionality on lease from the Provider. Service Provider Networks include Wireless Communications, Data Carriers, etc. IP Address: An IP address is a unique numerical identifier that is assigned to every device on a network. IP addresses are used to identify devices and enable communication between them. DNS: The [[Domain Name System (DNS)]](https://www.geeksforgeeks.org/domain-name-system-dns-in-application-layer/) is a protocol that is used to translate human-readable domain names (such as www.google.com) into IP addresses that computers can understand. Firewall: A [[firewall]](https://www.geeksforgeeks.org/introduction-of-firewall-in-computer-network/) is a security device that is used to monitor and control incoming and outgoing network traffic. Firewalls are used to protect networks from unauthorized access and other security threats. Types of Enterprise Computer Networks **LAN: **A [Local Area Network (LAN) ](https://www.geeksforgeeks.org/types-of-area-networks-lan-man-and-wan/)is a network that covers a small area, such as an office or a home. LANs are typically used to connect computers and other devices within a building or a campus. **WAN: **A [Wide Area Network (WAN)](https://www.geeksforgeeks.org/wan-full-form/) is a network that covers a large geographic area, such as a city, country, or even the entire world. WANs are used to connect LANs together and are typically used for long-distance communication. **Cloud Networks: **[Cloud Networks](https://www.geeksforgeeks.org/cloud-networking/) can be visualized with a Wide Area Network (WAN) as they can be hosted on public or private cloud service providers and cloud networks are available if there is a demand. Cloud Networks consist of Virtual Routers, Firewalls, etc. Class 12\] Explain any three types of networks - Computer Networks LAN Stands for Local Area Network, and connects devices within a building or campus. LANs are often used in small offices or homes and can provide high-speed data transfer and full-time service connectivity. MAN Stands for Metropolitan Area Network, and connects devices across a city, town, or other small region. MANs can be used to connect multiple LAN networks, and can provide high-speed regional resource sharing. MANs can use guided and unguided media, such as optical fibers or wireless infrastructure. WAN Stands for Wide Area Network, and connects devices across continents. WANs are the largest networks and can use technologies like microwave, radio, and fiber optic. WANs can be compatible with a variety of access lines and have advanced security, but their data transfer rates are usually lower than LANs.  What Is the Internet? The Internet is a worldwide network of interlinked computer networks that communicates with other networks and devices using the TCP/IP Internet protocol suite. Internet is a wide range of electrical, wireless, and optical networking technologies that connect the private, public, academic, corporate, and government networks in this network of networks, which spans local to global boundaries.  Email, phone calls, file sharing, and the World Wide Web\'s (WWW) interconnected hypertext pages and applications are just a few of the many information resources and services available over the Internet. One of the uses for the internet is web browsing. A web browser is an application that facilitates user interaction with all of the WWW\'s (World Wide Web) data. So what is WWW??? All public websites or web pages that people may access on their local computers and other devices through the internet are collectively known as the World Wide Web or W3. Users can get further information by navigating to links interconnecting these pages and documents. This data may be presented in text, picture, audio, or video formats on the internet. **Components of the Web** There are 3 components of the web: **Uniform Resource Locator (URL):** serves as a system for resources on the web.  **Hyper Text Transfer Protocol (HTTP):** specifies communication of browser and server.  **Hyper Text Markup Language (HTML):** defines the structure, organisation and content of a web page.  Difference Between WWW and Internet WWW Internet --------------------------------------------------------------------------------------------------- -------------------------------------------------------------------------------------------------------- It is originated in 1989. It is originated in 1960. WWW is an interconnected network of websites and documents that can be accessed via the Internet. Internet is used to connect a computer with other computer. WWW used protocols such as HTTP Internet used protocols such as [TCP/IP](https://www.geeksforgeeks.org/tcp-ip-in-computer-networking/) It is based on software. It is based on hardware. It is a service contained inside an infrastructure. There is a entire infrastructure in internet. Wi-Fi is a wireless networking technology, by which we can access networks or connect with other computers or mobile using a wireless medium. In Wi-Fi, data are transferred over radio frequencies in a circular range.  Wi-Fi is a wireless technology for networking, so it uses Electromagnetic waves to transmit networks. We know that there are many divisions of Electromagnetic waves according to their frequency such as X-ray, Gamma-ray, radio wave, microwave, etc, in Wi-Fi, the radio frequency is used. For transmitting Wi-Fi signal there is three medium,  Base station network or an Ethernet(802.3) connection: It is the main host network from where the network connection is provided to the router. Access point or router: it is a bridge between a wired network and a wireless network. It accepts a wired Ethernet connection and converts the wired connection to a wireless connection and spreads the connection as a radio wave. Accessing devices: It is our mobile, computer, etc from where we use the Wi-Fi and surfing internet. A sensor network is a group of sensors where each sensor monitors data in a different location and sends that data to a central location for storage, viewing, and analysis. There are many applications for sensor networks, from monitoring a single home, to the surveillance of a large city, to earthquake detection for the whole world.  Vehicular communication systems are computer networks in which vehicles and roadside units are the communicating nodes, providing each other with information, such as safety warnings and traffic information. They can be effective in avoiding accidents and traffic congestion. V2V communications allow vehicles to be continuously aware of each other. When one car brakes suddenly, for example, cars several yards behind the vehicle could get a safety warning before they get too close. PDF\] An Overview Of Vehicular Communications Semantic, 45% OFF Play this for difference : The World Wide Web (WWW or Web) serves a variety of functions, including: **1**. Information sharing  The Web allows individuals and organizations to easily share information with a global audience, including text, images, video, and other digital content. 2\. Communication The Web enables communication between individuals and groups through email, messaging, and social media platforms. 3\. Entertainment The Web provides access to a wide range of entertainment content, including music, movies, games, and other forms of digital media. 4\. E-commerce  The Web facilitates online commerce, allowing businesses to sell products and services directly to customers through websites and other digital channels. 5\. Education and research The Web provides access to vast amounts of educational and research content, including online courses, academic journals, and research databases. 6\. Collaboration The Web enables collaboration between individuals and groups, allowing them to work together on projects and share information in real-time. 7\. Personalization The Web allows users to personalize their online experiences through customized content, recommendations, and other features. 8\. Social networking  The Web provides a platform for social networking, allowing individuals to connect with others and share information and experiences All this possible with the help of certain tools like websites and webapplications. Some of the building blocks of these are webservers , web hosts , web browsers , underneath this lies http , html , xml , css , etc HTML (Hypertext Markup Language) for creating web pages URL (Uniform Resource Locator) for identifying the location of web pages HTTP (Hypertext Transfer Protocol) for transferring web page data between servers and clients. What is the World Wide Web? The World Wide Web, also known as the Web, is a system of interlinked hypertext documents accessed via the Internet. Who invented the World Wide Web? What is a URL? What is a web browser? What is HTML? What is HTTP? What is a search engine? What is a cookie? What is a hyperlink? What is a website? Information is powerful , it isn't the information but what can you do with it makes it powerful. If it is in the wrong hands it could lead to disaster. So we need to protect it. Information security is set of practices and protocols that help us to protect this information. Don't mistake it for cyber security there is often a confusion between both of them. Cybersecurity is all about securing the assests and infrastructure whereas information security is oabout securing the data Information Security programs are built around 3 objectives, commonly known as CIA -- Confidentiality, Integrity, Availability.  Confidentiality -- means information is not disclosed to unauthorized individuals, entities and process. For example, if we say I have a password for my Gmail account but someone saw while I was doing a login into Gmail account. In that case my password has been compromised and Confidentiality has been breached. Integrity -- means maintaining accuracy and completeness of data. This means data cannot be edited in an unauthorized way. For example, if an employee leaves an organisation then in that case data for that employee in all departments like accounts, should be updated to reflect status to JOB LEFT so that data is complete and accurate and in addition to this only authorized person should be allowed to edit employee data. Availability -- means information must be available when needed. For example if one needs to access information of a particular employee to check whether employee has outstanded the number of leaves, in that case it requires collaboration from different organizational teams like network operations, development operations, incident response and policy/change management.  So, a group of strategists sit to discuss about these traids and calculate the risks for it in their current company. Security Policies are then made to comply and achieve the goal. What exactly does cyber security do? Cybersecurity is the practice of protecting systems, networks, and programs from digital attacks. These cyberattacks are usually aimed at accessing, changing, or destroying sensitive information; extorting money from users via ransomware; or interrupting normal business processes. What is the concept of cybersecurity? Cybersecurity safeguards internet-connected systems, including hardware, software, and data, from malicious attacks. It\'s an essential practice for both individuals and businesses to defend against unauthorized access to critical information stored in data centers and other computer systems. Common types of cyber attacks Malware is a term used to describe malicious software, including spyware, ransomware, viruses, and worms. Malware breaches a network through a vulnerability, typically when a user clicks a dangerous link or email attachment that then installs risky software. Once inside the system, malware can do the following: Blocks access to key components of the network (ransomware) Installs malware or additional harmful software Covertly obtains information by transmitting data from the hard drive (spyware) Disrupts certain components and renders the system inoperable Phishing is the practice of sending fraudulent communications that appear to come from a reputable source, usually through email. The goal is to steal sensitive data like credit card and login information or to install malware on the victim's machine. Phishing is an increasingly common cyberthreat. Man-in-the-middle (MitM) attacks, also known as eavesdropping attacks, occur when attackers insert themselves into a two-party transaction. Once the attackers interrupt the traffic, they can filter and steal data. Two common points of entry for MitM attacks: 1\. On unsecure public Wi-Fi, attackers can insert themselves between a visitor's device and the network. Without knowing, the visitor passes all information through the attacker. 2\. Once malware has breached a device, an attacker can install software to process all of the victim's information. A denial-of-service attack floods systems, servers, or networks with traffic to exhaust resources and bandwidth. As a result, the system is unable to fulfill legitimate requests. Attackers can also use multiple compromised devices to launch this attack. This is known as a [distributed-denial-of-service (DDoS) attack](https://www.cisco.com/c/en/us/products/security/what-is-a-ddos-attack.html). Unit 5 IoT -- IoT stands for Internet of Things. It refers to the interconnectedness of physical devices, such as appliances and vehicles, that are embedded with software, sensors, and connectivity which enables these objects to connect and exchange data. This technology allows for the collection and sharing of data from a vast network of and sharing it with servers. Connected cars. Smart appliances. Connected security systems. Smart agriculture equipment. Connected retail. Connected healthcare monitors. Connected manufacturing equipment. Connected cities. Four Key Components of IOT Device or sensor Connectivity Data processing Interface IoT is network of interconnected computing devices which are embedded in everyday objects, enabling them to send and receive data.Over 9 billion 'Things' (physical objects) are currently connected to the Internet, as of now. In the near future, this number is expected to rise to a whopping 20 billion. Robotics- Robotics is a branch of engineering and computer science that involves the conception, design, manufacture and operation of robots. The objective of the robotics field is to create intelligent machines that can assist humans in a variety of ways. Robotics can take on a number of forms. A robot might resemble a human or be in the form of a robotic application, such as robotic process automation, which simulates how humans engage with software to perform repetitive, rules-based tasks. Safety Robots are able to carry out tasks in hazardous environments such as the inside of a nuclear power plant or deep underwater. They can also shield humans from dangerous situations by working alongside us, such as flying planes or driving cars. Time Saving Many repetitive and arduous tasks can be carried out by robots, which means we don't have to do them. This can increase productivity and free up time for more critical activities. Accessibility Robots offer people access to things that we wouldn't otherwise be able to do. For example, a robot could carry heavy objects or assist someone in moving from one place to another as a wheelchair does for those who need assistance walking. Surveillance Robots can be equipped with cameras to give us a view of places that would otherwise be inaccessible or too dangerous for humans. This includes bomb disposal robots that enter hazardous situations and gather information before experts decide how to proceed. Lessens Loneliness Artificial intelligence (AI) robotic companions can keep people company when they're alone, providing social interaction and making those who feel lonely less likely to become depressed. Whether it's a robot that performs tasks with the person or one that simply provides companionship, robotic "friends" can make life more fulfilling for people of all ages. Productivity Robots reduce human efforts and increase productivity within the workplace by taking on dangerous jobs that humans don't want to do. This could be mundane activities such as vacuuming or more complex jobs like assembling components in a factory-type environment. Improved Operation Robots can also improve the operation of systems such as computer networks and electrical grids. They can repair problems without people having to step in, which means greater productivity and faster response times if there is a need to fix an issue. Less Human Errors Robots can ensure better accuracy within the workplace, which reduces the likelihood of human error. When robots work alongside humans, they can help reduce mistakes by carrying out critical tasks without humans having to risk their lives.  Examples of space robots include the Curiosity and Perseverance Mars rovers, and the Ingenuity Mars helicopter. There are also humanoids like NASA\'s Robonaut and GITAI\'s G1, which may one day help build future orbiting stations and moon bases. Aquatic robots include uncrewed vehicles like Saildrone, long-duration ocean robots like Wave Glider, amphibian systems like the ACM-R5H snakebot and the Aqua hexapod, and deep-sea submersibles like Aquanaut.   Artificial Intelligence What is AI? Artificial intelligence, or AI, is technology that enables computers and machines to simulate human intelligence and problem-solving capabilities. Artificial Intelligence is not a magical program that can think like a human. The mechanism behind it is to utilise different mathematic algorithms to learn from a tremendous amount of structured data to solve dedicated cognitive problems that originally can be only solved by human intelligence. And the robust part of A.I. is it can acquire a pattern from the provided data to solve a problem in high accuracy. Meanwhile, we don't even know what is actually happening inside the program but the algorithm would take care of it. In a simple word, A.I. learns from the data feed by human to solve dedicated problem. **1. Computer Vision:**\ *e.g. Recognizing object from real world images or video, just like the iPhone X's Face ID.* **2. Planning:**\ *e.g. Searching for the shortest path between your home and the nearest shopping mall.* **3. Natural Language Processing:**\ *e.g. Interpreting what are you saying, writing, etc.* **4. Knowledge Representation and Reasoning:**\ *e.g. Chatbot that answer customer questions.* **5. Robotics:**\ *e.g. The self driving car that take care of your travel.* **6. Machine Learning:**\ *e.g Predicting the housing price by learning from the historical data.* Image and Video Processing : ---------------------------- Computer vision means the extraction of information from images, text, videos, etc. Sometimes computer vision tries to mimic human vision. It's a subset of computer-based intelligence or Artificial intelligence which collects information from digital images or videos and analyze them to define the attributes. The entire process involves image acquiring, screening, analyzing, identifying, and extracting information. This extensive processing helps computers to understand any visual content and act on it accordingly. Computer vision projects translate digital visual content into precise descriptions to gather multi-dimensional data. This data is then turned into a computer-readable language to aid the decision-making process. The main objective of this branch of Artificial intelligence is to teach machines to collect information from images. Applications of Computer Vision Medical Imaging: Computer vision helps in MRI reconstruction, automatic pathology, diagnosis, and computer aided surgeries and more. AR/VR: Object occlusion, outside-in tracking, and inside-out tracking for virtual and augmented reality. Smartphones: All the photo filters (including animation filters on social media), QR code scanners, panorama construction, Computational photography, face detectors, image detectors like (Google Lens, Night Sight) that we use are computer vision applications. Internet: Image search, Mapping, photo captioning, Ariel imaging for maps, video categorization and more. NLP: ----  Natural Language Processing (NLP) which is a fascinating and rapidly evolving field that intersects computer science, artificial intelligence, and linguistics. NLP focuses on the interaction between computers and human language, enabling machines to understand, interpret, and generate human language in a way that is both meaningful and useful. With the increasing volume of text data generated every day, from social media posts to research articles, NLP has become an essential tool for extracting valuable insights and automating various tasks. NLP powers many applications that use language, such as text translation, voice recognition, text summarization, and chatbots. You may have used some of these applications yourself, such as voice-operated GPS systems, digital assistants, speech-to-text software, and customer service bots. NLP also helps businesses improve their efficiency, productivity, and performance by simplifying complex tasks that involve language.  There are two main stages to the natural language processing process: - Data preprocessing, and - Algorithm development. The data preprocessing stage involves preparing or \'cleaning\' the text data into a specific format for computer devices to analyze. The preprocessing arranges the data into a workable format and highlights features within the text. This enables a smooth transition to the next step - the algorithm development stage - which works with that input data without any initial data errors occurring.