Module 1 Lesson 4_compressed.pdf

THE INTERNET AND THE WWW PREPARED BY: ANALYN V. CASIPE INTRODUCTION The terms “INTERNET” and “WORLD WIDE WEB” may seem interchangeable at first. In everyday conversation, they serve the same purpose, though the latter has not been used much in recent years.  WHAT IS THE INTERNET? a...

THE INTERNET AND THE WWW PREPARED BY: ANALYN V. CASIPE INTRODUCTION The terms “INTERNET” and “WORLD WIDE WEB” may seem interchangeable at first. In everyday conversation, they serve the same purpose, though the latter has not been used much in recent years.  WHAT IS THE INTERNET? a massive public network of networks. It is like a global computer, wherein each individual computer or server becomes just another node in one massive, distributed system. Today, the standard office building or corporation might have an intranet, which is the same type of computer/information network, only privatized to limit and control access.  WHAT IS THE INTERNET? it had genesis in the US Department of Defense, as a concept being explored by the Advanced Research Projects Agency (ARPA) in the 1960s. The Internet came first, and the World Wide Web followed Capitalizing the “I” is grounded in both history and grammar using lower case when refer to a general network connection not associated with the World Wide Web.  WHAT IS THE WORLD WIDE WEB? or just “The Web” , is a standardized system for accessing and navigating the Internet. Is distinguished from other systems by its use of HTTP, which in turn is just a system for standardizing the use of HTML. HTML is the language of the Web, and HTTP is the language of business.  WHAT IS THE WORLD WIDE WEB? Having a language in common allows us to communicate, understand one another, and share ideas or information, standardized HTML usage allows everyone accessing the Internet through the Web. accessing the Web requires a Web browser (Internet Explorer, Chrome, Safari, or Firefox), to make sense of HTML and allow Web pages to display properly.  NOTE: Internet - 1960 World Wide Web - 1991 SEARCH ENGINES AND THE WEB  SEARCH ENGINES AND THE WEB If HTTP is the grammar of the Web, and HTML is the language, then links might be the punctuation. Links are the architecture of the Web, which the browsers use to navigate, and users share to connect one another LINKS, MOBILE APPS, AND DATA: WEB VS INTERNET  INTERNET AND WORLD WIDE WEB When we talk about SEARCH, we are really talking about WEB SEARCH, and that means links. COMPUTER NETWORK WHAT IS COMPUTER NETWORK? It is a set of computers connected together for the purpose of sharing resources. NODES Computers on a network are called nodes. The connection between computers can be done via cabling. CONNECTED COMPUTERS Can share resources like access to the Internet, printers, file servers, and other. COMPUTER NETWORK NETWORK is a multipurpose connection, which allows a single computer to do more than it could without any connection. DATA COMMUNICATION AND COMPUTER NETWORK DATA COMMUNICATION AND COMPUTER NETWORK Data communication refers to the transmission of this digital data between two or more computers. Computer Network is a telecommunications network that allows computers to exchange data. The best-known computer network is the Internet. WHAT IS A PACKET? In networking, a packet is a small segment of a larger message. Data sent over computer networks, such as the Internet, is divided into packets. Packets are recombined by the computer that receives them.  TYPES OF COMPUTER NETWORKS The size of a network should be expressed by the geographic area and number of computers, which are a part of their networks It includes devices housed in a single room to millions of devices spread across the world.  TYPES OF COMPUTER NETWORKS Some of the most popular network types are: PAN LAN MAN WAN  PERSONAL AREA NETWORK (PAN) Is a computer network formed around a person. It consists of a computer, mobile, or personal digital assistant. Can be used for establishing communication among these personal devices for connecting to a digital network and the internet.  CHARACTERISTICS OF PAN: Personal devices network equipped within a limited area Allows to handle the interconnection of IT devices at the surrounding of a single user. Includes mobile devices, tablet, and laptop Can be wirelessly connected to the internet called WPAN. Appliances use for PAN: cordless mice, keyboards, and Bluetooth systems  ADVANTAGES OF PAN: PAN networks are relatively secure and safe. It offers only short-range solution up to ten meters. Restricted to a small area.  DISADVANTAGES OF PAN: It may establish a bad connection to other networks at the same radio bands. Distance limits.  LOCAL AREA NETWORK (LAN) Is a group of computer and peripheral devices which are connected in a limited area such as school, laboratory, home, and office building. Is a widely useful network for sharing resources Simplest type of LAN network is to connect computers and a printer in someone’s home or office. LOCAL AREA NETWORK (CONT.) LAN will be used as one type of transmission medium. Is a network which consists of less than 5000 interconnected devices across several buildings.  CHARACTERISTICS OF LAN: Is a private network. LAN operates at a relatively higher speed compared to other WAN systems. There are various kinds of media access control methods like token ring and ethernet.  ADVANTAGES OF LAN: Computer resources like hard-disks, DVD-ROM, and printers can share local area networks. You can use the same software over the network. Data of all network users can be stored on a single hard disk of the server computer.  ADVANTAGES OF LAN: (CONT.) Can easily transfer data and messages over networked computers. Easy to manage data at only one place offers the facility to share a single internet connection among all the LAN users.  DISADVANTAGES OF LAN: LAN save cost, but installing LANs is quite high. LAN admin can check personal data files of every LAN user Unauthorized users can access critical data of an organization. It requires a constant LAN admin as there are issues related to software setup and hardware failures. WIDE AREA NETWORK Is a computer network which is spread across a large geographical area. WAN network system could be a connection of a LAN which connects with other LAN’s using telephone lines and radio waves. Is mostly limited to an enterprise or an organization.  CHARACTERISTICS OF WAN: The software files will be shared among all the users Any organization can form its global integrated network using WAN.  ADVANTAGES OF WAN: It helps to cover a larger geographical area. It contains devices like mobile phones, laptop, tablet, computers, gaming consoles, etc. WLAN connections work using radio transmitters and receivers built into client devices.  DISADVANTAGES OF WAN: Initial setup cost of investment is very high. Difficult to maintain WAN network. More errors and issues because of the wide coverage and use of different technologies. It requires more time to resolve issues Offers lower security  WHAT IS MAN? Metropolitan Area Network (MAN) is consisting of a computer network across an entire city, college campus, or a small region.  CHARACTERISTICS OF MAN mostly covers towns and cities in a maximum 50 km range Mostly used medium is optical fibers, cables. Data rates adequate for distributed computing applications.  ADVANTAGES OF MAN It offers fast communication using high-speed carriers (fiber optic cables) It provides excellent support for an extensive size network and greater access to WANs. The dual bus in MAN network provides support to transmit data in both directions concurrently. Mostly includes some areas of a city or an entire city.  DISADVANTAGES OF MAN You need more cable to establish MAN connection from one place to another. In MAN network it is tough to make the system secure from hackers. OTHER TYPES OF NETWORKS WLAN (Wireless Local Area Network Storage Area Network System Area Network Home Area Network POLAN- Passive Optical LAN Enterprise private network Campus Area Network Virtual Area Network  WIRELESS LOCAL AREA NETWORK (WLAN) It helps you to link single or multiple devices using wireless communication within a limited area (home, school, or office building) WLAN systems are based on IEEE 802.11 standards.  STORAGE AREA NETWORK (SAN) Is a type of network which allows consolidated, block-level data storage. Used to make storage devices (disk arrays, optical jukeboxes, tape libraries)  SYSTEM AREA NETWORK Is used for a local network Offers high-speed connection in server-to-server and processor- to-processor applications  PASSIVE OPTICAL LOCAL AREA NETWORK Is a networking technology which helps to integrate into structured cabling Allows you to resolve the issues of supporting Ethernet protocols and network apps.  HOME AREA NETWORK (HAN) Two or more interconnected computers to form a local area network (LAN) within the home Helps computer owners to interconnect with multiple computers. Allows sharing files, programs, printers, and other peripherals.  ENTERPRISE PRIVATE NETWORK Are build and owned by businesses to securely connect numerous locations.  CAMPUS AREA NETWORK (CAN) Made up of an interconnection of LANs within a specific geographical area.  VIRTUAL PRIVATE NETWORK Is a private network which uses a public network to connect remote sites or users together. VPN network uses “virtual” connections routed through the internet from the enterprise’s private network or a third-part VPN service to the remote site. TOPOLOGY  BUS TOPOLOGY Is a network type in which every computer and network device is connected to single cable.  RING TOPOLOGY It forms a ring as each computer is connected to another computer, with the last one connected to the first.  STAR TOPOLOGY All computers are connected to a single hub through a cable. The hub is the central node  MESH TOPOLOGY Is a point-to-point connection to other nodes or devices. Mesh has n(n-1)/2 physical channels to link n devices.  MESH TOPOLOGY: ROUTING The nodes have a routing logic, as per the network requirements.. Routing logic to direct the data to reach the destination using the shortest distance.  MESH TOPOLOGY: FLOODING The same data is transmitted to all the network nodes, hence no routing logic is required.  TREE TOPOLOGY It has a root node and all other nodes are connected to it forming a hierarchy. Also called hierarchical topology. (should have at least three levels to hierarchy)  HYBRID TOPOLOGY It is two different types of topologies which is a mixture of two or more topologies. BASIC NETWORK HARDWARE NETWORK CABLES Are the transmission media to transfer data from one device to another. Category 5 cable with RJ-45 connectors ROUTERS A connecting device that transfers data packets between different computer networks. Used to connect a PC or an org’s LAN to a broadband internet connection. Contain RJ-45 ports so that computers and other devices REPEATERS, HUBS & SWITCHES A repeater receives a signal and regenerates before re-transmitting A hub is a multiport repeater having several input/output ports A switch receives data from a port, uses packet switching to resolve the destination device and forwards the data to the particular destination. BRIDGES It connects two separate Ethernet network segments. It forwards packets from the source network to the destined network. GATEWAYS It connects entirely different networks that work upon different protocols It is the entry and the exit point of a network NETWORK INTERFACE CARDS is a component of the computer to connect it to a network. Two types of NIC: Internal Network Cards External Network Cards NETWORK INTERFACE CARDS is a component of the computer to connect it to a network. Two types of NIC: Internal Network Cards External Network Cards