Using the form placed in the homepage you can get all the games that match a search criteria like player's name, ECO code, number of moves, etc
You can also search a position here. This outstanding tools is unique and really powerful!
You should specify at least one player name or an ECO code or an Opening name. Otherwise the search result would be too big and useless.
Yes. You can go to the Search Position page, make some moves dragging and droping the pieces over the board and then press the Search button.
In order to increase performance the search engine is restricted and you should enter at least 3 moves for each color. For example: 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6
If you have a game in PGN notation you can paste it in the moves area, up in the right side, and press the Apply Game button. Then you can move back and forward through the game and search a given position.