ChessBase is the dominant commercial database program for storing and searching records of games of chess.
In addition to permitting searches for games or positions in games based on player names, openings, or features of the position, it includes chess analysis tools based on the computer chess programs Fritz and Crafty. For many serious chess players, ChessBase and similar programs complement and sometimes substitute for printed opening manuals and chess game collections.
ChessBase uses a proprietry format for storing games, but can also handle games in portable game notation.
There are a number of other commercial chess database programs, among them Chess Assistant. There are also a several free alternatives, including SCID, which is released under the GNU GPL.
ChessBase is also the name of the company that markets the ChessBase program and other software related to chess.