OK, I'll give it a shot.
The CAN interface is the hardware of the system. It is the 9 pin D-sub and the cables that are connected to it. It is also the driver for that hardware. It can also be the information passing on that cable.
The CAN channel is a particular piece of datum that is transfered via the interface. There are two ways to thing of the data transfered via CAN: Frames and Channels. Frames are a message including its header and data. Cahnnels are the individual packets of data in the message.
Analogy: Grocery list.
Channels are the items on the list.
Message is today's list.
Interface is pen and paper for creating, reading,and checking off the list.
Hope that this helps!
Bob Young
