Computer Networking Basics

Technology in Action - Chapter 7: Networking: Connecting Computing Devices

• Chapter 7 covers networking, connecting computing devices.
• Learning objectives include describing computer networks, their pros and cons, different ways networks are defined, transmission media types, necessary hardware and software, broadband Internet access options, wireless Internet, home network setup, wireless home network problems, and solutions, and wireless home network security.
• A computer network connects two or more computers to communicate. Each device on a network is a node, which can be a computer, peripheral (like a printer), or network device (like a router).
• Networks offer benefits like sharing high-speed internet, printers, peripheral devices, and files, and enable common communication.
• A disadvantage of networks is setup time.
• Data transfer rate (bandwidth) is the maximum transmission speed. Throughput is the actual speed data is transferred. Measured in Mbps (megabits per second) or Gbps (gigabits per second).
• Networks can be classified by distance. Types include PANs, LANs, HANNs, MANs, and WANs.
• Networks can also be classified by levels of administration, such as client-server networks and peer-to-peer networks.
• In client-server networks, clients request services from a server. Peer-to-peer networks let each node communicate directly with every other node.
• Networks use protocols and transmission media (wireless or wired) to connect nodes. Wired networks use UTP, coaxial, or fiber-optic cables.
• Network components include network adapters (NICs), modems (translate signals), routers (transfer data between networks), and switches (manage data flow).
• Network software includes operating systems for P2P networking and client-server networks that use centralized servers for communication
• Essential elements for a functioning network include connection methods(cables or wireless), special hardware (allowing nodes to communicate) and software.
• Broadband internet connections are commonly used. They include cable internet, DSL, and fiber-optic service.
• Wireless internet access methods include mobile broadband, mobile hotspots, and wireless ISPs.
• Important considerations for home network setup include listing all devices, using the latest standards, and using the newest equipment
• Specialized home networking devices include NAS devices (network-attached storage), home network servers, and network-ready devices, designed to improve data management in a network.
• Troubleshooting wireless problems might involve placing access points where the signal is weak and using wireless range extenders.
• Securing wireless networks involves using encryption, changing network names(SSID), disabling SSID broadcast, changing default passwords, and creating passphrases. Additional methods include using media access controls, limiting signal range, keeping router firmware updated, and disabling remote access.

Technology in Action - Chapter 9: Securing Your System: Protecting Your Digital Data and Devices

• Cybercrime is criminal activity using computers, networks, and the internet (e.g., fraud, identity theft). Cybercriminals are individuals who perpetrate such crimes. Common types include FBI-related scams, identity theft, non-delivery/non-auction fraud, and advance-fee fraud.
• Identity theft occurs when a thief steals personal information to impersonate someone. Common scams include counterfeiting cards, changing addresses, opening new accounts, and obtaining medical/housing services.
• Hacking involves unauthorized access to computer systems. Types include white-hat (ethical), black-hat (illegal), and grey-hat. Tools include packet analyzers (sniffers) and keyloggers.
  • Trojan horses are programs disguised as useful tools, but which have hidden malicious code
  • Backdoors and rootkits allow unauthorized access to a computer.
• Denial-of-service (DoS) attacks flood a system with requests, preventing legitimate users from accessing it.
  • Zombies are computers under a hacker's control, often used in DDoS (distributed DoS) attacks.
  • Botnets are groups of zombie computers used to launch coordinated attacks.
• Exploit kits are software used to find and exploit vulnerabilities in servers.
• Viruses are programs that attach to other programs to spread to other computers. They aim to replicate, copy, and often damage host files.
  • Viruses can be classified by techniques that avoid detection:
• Polymorphic: changes code
• Multi-partite: affects multiple files
• Stealth: erases code, hides in memory.
• Malware includes adware, spyware, and keystroke loggers that run with malicious intent.
  • Adware shows sponsored advertisements.
  • Spyware gathers information without user knowledge.
  • Keystroke loggers monitor keystrokes.
• Spam is unwanted email or software. Spam filters help in reducing spam.
• Cookies are small text files that websites store on your hard drive; they can be used to track website traffic and personalize user experiences, but do not invade privacy unless exploited by others.

Technology in Action - Chapter 10: Behind the Scenes: Software Programming

• Programming tasks include complex tasks requiring creative thought and handling repetitive work with electronic information or clear steps to achieve automation.
• A career in programming offers plentiful jobs, strong salaries, and telecommuting opportunities. Programming is necessary when there's no existing software for a task.
• An Information System includes a collection of interacting parts (data, people, procedures, hardware, and software) that work together toward a common goal.
• Steps in the System Development Life Cycle (SDLC) include identifying the problem, analyzing the problem, designing a solution, developing the software, testing and installing, and maintaining the system.
• The stages of the program development life cycle (PDLC) involve defining the problem, developing the algorithm, converting the algorithm into code in a specific programming language, testing the program, and preparing documentation to explain the program to others.
• A programming language is a code used to tell the Central Processing Unit (CPU) what to do.
• Programming languages can be classified by generations (e.g., first-generation).
• Programming languages also use portability—the ability to move a program to another computer—and often use variables. Variables are used to tell the system how much space to allocate for inputs and outputs, and comments are used to describe the purpose of code portions.
• Compilation converts programs into machine code, and interpreters convert them into intermediate forms.
• Integrated Development Environments (IDEs) help programmers write and test programs.
• Debugging involves finding and fixing program errors.

Technology in Action - Chapter 11: Behind the Scenes: Databases and Information Systems

• Database advantages include efficient management of data, information sharing, and ensuring data accuracy and reliability.
  • A database stores related data and can be queried (viewed) and manipulated.
• Flat databases organize data in a simple table format but can suffer from data redundancy, inconsistency, inappropriate data, and incomplete data. Relational databases organize data into related tables, connecting them through common fields (one-to-many, one-to-one, many-to-many).
• Database Management Systems (DBMS) are software which use keys like primary keys to uniquely identify records in related tables and foreign keys to link those records.
  • Data validation ensures the data entered in the database is valid based on expectations established for that particular field.
• Viewing, sorting, and extracting data in a database can be done using queries, filters, or other tools, and data output can be a report or exported to other applications.
• Data warehousing and storage can track data to analyze trends (e.g. sales, customer demographics). Data mining uses techniques like anomaly detection, association grouping, classification, clustering, and visualization to identify patterns and insights in data.

Test your understanding of computer networking fundamentals with this quiz. It covers essential concepts such as internet access, wireless networks, data storage, and network types. Perfect for beginners looking to enhance their knowledge of networking.