 Circuit switching
Circuit switching requires a dedicated channel between any two nodes
of communication, this channel cannot be used by any other users while
the transmission is going between the two nodes if the channel’s
capacity is fully utilized, this causes bandwidth wastage, see the figures
below.
• For the figures Let’s assume that we have only the channels drawn.
This figure demonstrates the concept of a dedicated channel, used
channels cannot be shared.
This figure demonstrates the bandwidth wastage caused by packet
switching.
 Packet switching:
Packets switching decomposes the data first into packets at the source,
and then it is reassembled at the destination, see the figures below.
• Notice in the figure above, all users are using the same two channels
at the same time.
• This also solves the problem of bandwidth wastage since underutilized channels can be used when needed.
• Note: there are some disadvantages of packet switching such as that
some packets may get lost due to the shutdown off a path for
example (since they travel in different roots) but this problem can be
solved easily by just resending the lost packet.