Packet switch and message switch?

packet switching can be considered an improvement over message switching.Similar to message switching,packet switching forwards data on first come first serve basis between nodes and no dedication connection is made (as it is done in circuit switching).

But unlike message switching,packet switching puts an upper limit on the maximum size of the packet.If the packet size is greater than the maximum,it is segmented and then transmitted.Each segment has separate header which increases the overhead. But it reduces the average delays.Also in case of packet switching data is not stored for later transmission to a currently busy or inactive terminal.It just takes care of data transmission between nodes