What is Wireshark? 

Wireshark is a network packet analyzer. A network packet analyzer will try to capture network packets and tries to display that packet data as detailed as possible.
You could think of a network packet analyzer as a measuring device used to examine what's going on inside a network cable, just like a voltmeter is used by an electrician to examine what's going on inside an electric cable (but at a higher level, of course).
In the past, such tools were either very expensive, proprietary, or both. However, with the advent of Wireshark, all that has changed. Wireshark is perhaps one of the best open source packet analyzers available today.

Some intended purposes
 Here are some examples people use Wireshark for:
• network administrators use it to troubleshoot network problems.
• network security engineers use it to examine security problems.
• developers use it to debug protocol implementations.
• people use it to learn network protocol internals.
 
Features

The following are some of the many features Wireshark provides:
• Available for UNIX and Windows.
• Capture live packet data from a network interface.
• Open files containing packet data captured with tcpdump/WinDump, Wireshark, and a number of other packet capture programs.
• Import packets from text files containing hex dumps of packet data.
• Display packets with very detailed protocol information.
• Save packet data captured.
• Export some or all packets in a number of capture file formats.
• Filter packets on many criteria.
• Search for packets on many criteria.
• Colorize packet display based on filters.
• Create various statistics.

Interface Look like this ,