'CAN' is most like a TV-Broadcasting.

You can tune into a channel to receive data from that channel.

You can send 'messages' into your own channel (this message-channel is made unique with an identifier specified by the sending station)

You will find to types of CAN messages.
11bit ID's and 29bit ID's.

You may not or must avoid sending into someone else channel. This causes bus-errors.

The CAN-bus is Carrier sense and therefore ZERO promoting.

An ID = 0 has the highest priority.

You can send within a message max 8 bytes!

What kind of hardware (uP) do you use.

PS. : It's very simple, you CAN use it at ease.

PS. : CAN-open is a overlaying layer on top of CAN.