3 NETWORK DEVICES I HAVE STUDIED ABOUT: 1- NETWORK HUB: An Ethernet hub, active hub, network hub, repeater hub, multiport repeater or hub is a device for connecting multiple Ethernet devices together and making them act as a single network segment. It has multiple input/output (I/O) ports, in which a signal introduced at the input of any port appears at the output of every port except the original incoming. A hub works at the physical layer (layer 1) of the OSI model.[1] The device is a form of multiport repeater. Repeater hubs also participate in collision detection, forwarding a jam signal to all ports if it detects a collision. Some hubs may also come with a BNC and/or Attachment Unit Interface (AUI) connector to allow connection to legacy 10BASE2 or 10BASE5 network segments. The availability of low-priced network switches has largely rendered hubs obsolete but they are still seen in 20th century installations and more specialized applications. FROM : http://en.wikipedia.org/wiki/Ethernet_hub 2- SWITCH: A network switch or switching hub is a computer networking device that connects network segments or network devices. The term commonly refers to a multi-port network bridge that processes and routes data at the data link layer (layer 2) of the OSI model. Switches that additionally process data at the network layer (layer 3) and above are often referred to as layer-3 switches or multilayer switches. The first Ethernet switch was introduced by Kalpana in 1990.[1] FROM: http://en.wikipedia.org/wiki/Network_switch 3- ROUTER: A router is a device that forwards data packets between computer networks, creating an overlay internetwork. A router is connected to two or more data lines from different networks. When a data packet comes in on one of the lines, the router reads the address information in the packet to determine its ultimate destination. Then, using information in its routing table or routing policy, it directs the packet to the next network on its journey. Routers perform the "traffic directing" functions on the Internet. A data packet is typically forwarded from one router to another through the networks that constitute the internetwork until it gets to its destination node.[1] The most familiar type of routers are home and small office routers that simply pass data, such as web pages and email, between the home computers and the owner's cable or DSL modem, which connects to the Internet through an ISP. More sophisticated routers, such as enterprise routers, connect large business or ISP networks up to the powerful core routers that forward data at high speed along the optical fiber lines of the Internet backbone. FROM : http://en.wikipedia.org/wiki/Router_(computing)

BLOGS: ((A blog (a portmanteau of the term web log)[1] is a personal journal published on the World Wide Web consisting of discrete entries ("posts") typically displayed in reverse chronological order so the most recent post appears first. Blogs are usually the work of a single individual, occasionally of a small group, and often are themed on a single subject. Blog can also be used as a verb, meaning to maintain or add content to a blog. The emergence and growth of blogs in the late 1990s coincided with the advent of web publishing tools that facilitated the posting of content by non-technical users. (Previously a knowledge of such technologies as HTML and FTP had been required to publish content on the Web.) Although not a must, most good quality blogs are interactive, allowing visitors to leave comments and even message each other via GUI widgets on the blogs and it is this interactivity that distinguishes them from other static websites.[2] In that sense, blogging can be seen as a form of social networking. Indeed, bloggers do not only produce content to post on their blogs but also build social relations with their readers and other bloggers.[3] Many blogs provide commentary on a particular subject; others function as more personal online diaries; yet still others function more as online brand advertising of a particular individual or company. A typical blog combines text, images, and links to other blogs, Web pages, and other media related to its topic. The ability of readers to leave comments in an interactive format is an important part of many blogs. Most blogs are primarily textual, although some focus on art (art blog), photographs (photoblog), videos (video blogging or vlogging), music (MP3 blog), and audio (podcasting). Microblogging is another type of blogging, featuring very short posts. As of 16 February 2011, there were over 156 million public blogs in existence.[4)) -AS SEEN ON :http://en.wikipedia.org/wiki/Blog

FORUMS:

An Internet forum, or message board, is an online discussion site where people can hold conversations in the form of posted messages.[1] They differ from chat rooms in that messages are at least temporarily archived. Also, depending on the access level of a user or the forum set-up, a posted message might need to be approved by a moderator before it becomes visible. Forums have a specific set of jargon associated with them; e.g. a single conversation is called a "thread". A discussion forum is hierarchical or tree-like in structure: a forum can contain a number of subforums, each of which may have several topics. Within a forum's topic, each new discussion started is called a thread, and can be replied to by as many people as so wish. Depending on the forum's settings, users can be anonymous or have to register with the forum and then subsequently log in in order to post messages. On most forums, users do not have to log in to read existing messages.

AS SEEN FROM: http://en.wikipedia.org/wiki/Internet_forum

WIKIS: ((A wiki (i/ˈwɪkiː/ wik-ee) is a website whose users can add, modify, or delete its content via a web browser using a simplified markup language or a rich-text editor.[1][2][3] Wikis are powered by wiki software. Most are created collaboratively. Wikis may serve many different purposes, such as knowledge management and notetaking. Wikis can be community websites and intranets, for example. Some permit control over different functions (levels of access). For example, editing rights may permit changing, adding or removing material. Others may permit access without enforcing access control. Other rules may also be imposed for organizing content. Ward Cunningham, the developer of the first wiki software, WikiWikiWeb, originally described it as "the simplest online database that could possibly work."[4] "Wiki" (pronounced [ˈwiti] or [ˈviti]) is an Hawaiian word meaning "fast" or "quick".[5])) -AS MENTIONED ON WIKIPEDIA. SOURCE : http://en.wikipedia.org/wiki/Wiki