Difference between synchronous bus and asynchronous bus?

1. Syncrhonous bus includes clock in control lines whereas asynchronous bus is not clocked.

2. the devices which need to be connected by synchronous bus should be at same speed whereas an asynchronous bus may connect many devices with varying speeds.

3. A fixed protocol is defined to communicate using synchronous bus which is relative to the clock. An asynchronous bus uses handshaking protocol.