Application Layer (Layer 7)

When a user using a computer and open an application program and if that application program is going to use the internet, it gives work to the application layer. In other way application layer provides services to the application program to make the communication with another application program.

The following services provided at the Application Layer: 
·        Finds out the other end party is discover. 
·        Whether the requested data exists. 
·        Error recovery, data integrity, and privacy.

·        All communication between applications requires cooperation (synchronization).

Some of the protocols that are used at the Application layer:
·   HTTP (Hypertext Transfer Protocol)
·   FTP (File Transfer Protocol)
·   SMPT (Simple Mail Transfer Protocol)
·   DHCP (Dynamic Host Configuration Protocol)
·   DNS (Domain Name System) 
·    Telnet