If you're buying a board and already have bindings, pay attention to the inserts and make sure your bindings fit there. You will find an incompatibility if you have bindings for the standard 4x2 or 4x4 inserts and buy a burton board with the channel system, or if you have burton bindings for the channel system and get a board with standard inserts. However, you'll probably find some binding discs that fit your bindings and board inserts, so dont worry.
4x2 standard inserts The standard ones, featured in most snowboards. The 4x2 inserts are 4cm apart from each other (heel side to toe side) X 2cm (nose to tail). They'll give you more stance width options than the 4x4 inserts. For all bindings except the burton ones made for the channel system.
4x4 standard inserts Not that used this days. The 4x4 inserts 4cm apart from each other in both directions. For all bindings except the burton ones made for the channel system.
burton 3D inserts Only on burton snowboards.
burton est system (channel) Only on burton snowboards.