What is the BitTorrent Client?

The BitTorrent Client is an application that allows you to use the BitTorrent Protocol for downloading and uploading a variety of large file types quickly.

Where normal downloading through a browser is done linearly, what makes the Bittorrent protocol unique is that it allows parts of a file to be downloaded simultaneously from different sources and out-of-order. The Client assembles these parts into the complete file. Once a part of the file is downloaded, the BitTorrent Client makes that part available to other BitTorrent users (peers). When the file is completely downloaded, the Client will seed the file, making the entirety available for peers.

Many clients exist for torrenting, each with its own advantages. We recommend downloading only the BitTorrent or uTorrent Clients. While some other clients may offer attractive features, BitTorrent does not support clients beyond those we recommend.

The BitTorrent Client offers many advanced features that may be confusing to the user. The Client is configured correctly when it is installed, and should require no configuration changes under normal network conditions.

Check for more: http://bundle-help.bittorrent.com/customer/en/portal/articles/1636317-what-is-the-bittorrent-client-