Chess Diagrams
FEN Notation
PGN Notation
PGN stands for Portable Game Notation and is a standard recording format for chess games. PGN tracks individual moves, not just the current state unlike FEN Notation.
Image Generation
Chess.com can generate static images of gameplay as well as GIFs of movesets. Static images use FEN Notation and the GIFs accept either PGN Format or a Chess.com link.