File Sharing
File sharing means, the users can download files from internet and from other networks. Normally the file sharing system use the p2p (Peer to Peer) system, in this system the files are stored in a server and can be downloading by the user. File sharing programs are installed on the system, in order to continue the process. In this model people can also share their files, and other can download these files. In peer to peer network file sharing system you can only download files, but can not upload the files. But some systems are also granted permission of uploading the files. File sharing is data protection solution of your important data, through this you can take online backup of your data.

File transfer is one of the major uses of internet. Either it is by e-mail or by FTP. FTP is a normally used a method for sharing the files. In this method you can download or upload the files. The file sharing system is most commonly used after the popularity of MP3 files. These files are small in size and can easily uploaded on web sites. Today’s much software’s are available which can be used for file sharing system on different networks. This software is also operating system dependent. Different networks and operating systems are working on different structures. Online data backup service is a great feature of file sharing; you can take the backup of your data online. File sharing system can be used to take back up and can be used for data recovery.

Classifications Of Peer-To-Peer Network
A peer to peer file sharing network can be classified into many types. Some of the types are discussed below.

Centralized P2P Network
In this p2p file sharing technique, the user sends a request to the central computer or server for wanted file, such as music file sharing or a document file. The server or computer search this file and answer back to the computer that data found or not, or send a list of peers, which have this kind of data. After this connection is establish for downloading data. Free file sharing is also offered by some peer to peer file sharing companies.

Anonymous P2P Applications
In this type, the anonymity features are provided in peer to peer network. RShare, Free net, I2P, GNU net are all examples of anonymous peer to peer network
Friend-to-friend networks only already familiar users can connect to your system. After this the request is forwarded to the friends nodes.

Web Based File Sharing
Web based file sharing system is the alternative of peer-to-peer file sharing system. This one click hosting service gives you the space from 100 MB to 1.5GB. Mostly the users upload the file link on different forums or site, or they can share their file by using the e-mail services. Web based file sharing is providing you online data backup services.