Message Switching

Message is a piece of information. Switching means movement. 

In a Network there are a number of nodes. Nodes are vital junctions of a Network. Message Switching means transmission from one node ( one point ) of a Network to another node ( another point ). So, transmission is from point to point. Transmission from one point to another point is a single hop ( jump ).

Message Switching means switch over of a Message. In one step of Message Switching,  Message switches over from one node to another. 

The two nodes involved in a Switching operation are on the same Network. It cannot be that the beginning node ( source node) is on one Network and the second node ( sink node ) is on a different Network.

In a point to point ( one junction to another junction ) transmission, a Message travels a part of its journey. Message moves from previous point to next point. The Network is Point-to-Point Network.

A Switching activity means movement of a message. Indeed, the Message has moved from one node to the next node.The first node is the first point. The second node  is the second point. So, Message Switching here is from point to point.

A Message has to go from starting node ( first point ) to last node ( last point ). There can be many point to point transmissions involved in such a case. Because, there may be many points in a network between first point and last point.

Firstly, transmission of a message occurs from first point to second point. Next, a second point to third point transmission ( of the same Message ) can follow. And so on. In this way a Message makes its way through a point-to-point Network.

Clearly, in case of Message Switching the previous node and next node are involved. Message Switching occurs between two nodes, placed next to next. 

The previous node is the source node. The next node is the sink node. The first transmission involving a Message has one set of a source node and a sink node. In successive transmissions, the source and sink are different.

A series of Message Switching operations are required. Message starts from the first node of a Network. Finally, it reaches the last node. Last node of the Network sees the last switching operation.