WHAT IS 'LAN'???

  WHAT IS "LAN"???  

LAN is a Local area networks (LANs) are computer networks ranging in size from a few computers in a single office to hundreds or even thousands of devices spread across several buildings. They function to link computers together and provide shared access to printers, file servers, and other services. LANs in turn may be plugged into larger networks, such as larger LANs or wide area networks (WANs), connecting many computers within an organization to each other and/or to the Internet.

Because the technologies used to build LANs are extremely diverse, it is impossible to describe them except in the most general way. Universal components consist of the physical media that connect devices, interfaces on the individual devices that connect to the media, protocols that transmit data across the network, and software that negotiates, interprets, and administers the network and its services. Many LANs also include signal repeaters and bridges or routers, especially if they are large or connect to other networks.

The level of management required to run a LAN depends on the type, configuration, and number of devices involved, but in some cases it can be considerable.

WHAT IS PROTOCOL?? 

In information technology, a protocol is the special set of rules that end points in a telecommunication connection use when they communicate. Protocols specify interactions between the communicating entities. 

Protocols exist at several levels in a telecommunication connection. For example, there are protocols for the data interchange at the hardware device level and protocols for data interchange at the application program level. In the standard model known as Open Systems Interconnection (OSI), there are one or more protocols at each layer in the telecommunication exchange that both ends of the exchange must recognize and observe. Protocols are often described in an industry or international standard.

The TCP/IP Internet protocols, a common example, consist of :

• Transmission Control Protocol (TCP), which uses a set of rules to exchange messages with other Internet points at the information packet level
• Internet Protocol (IP), which uses a set of rules to send and receive messages at the Internet address level
• Additional protocols that include the Hypertext Transfer Protocol (HTTP) and File Transfer Protocol (FTP), each with defined sets of rules to use with corresponding programs elsewhere on the Internet