A CHAT file is a configuration file used by the IRC (Internet Relay Chat) for connecting to an IRC channel. It contains connection parameters such as server, port, name of the IRC channel, and optionally a password for opening an IRC channel. The settings are used by the client to connect to other channels. The chats and discussions on IRC are one-to-one and are private.
Applications that can open CHAT files include mIRC and Visual IRC.
CHAT File Format
CHAT files are stored as binary files to disc. When a user wants to connect to a channel in IRC, he enters the the informaiton in the iRC client, he enters the information in the client software. The information is stored in the CAHT file for lateral retrieval.