MPLS Lable : PUSH / POP / SWAP

In MPLS Lable  we come with the terms know as PUSH , POP & SWAP & always we get confuse with there function.

Here is the brief of  PUSH , POP & SWAP :

1] PUSH  :  Adding a Lable to Incomming Packet and also aka Lable imposition
2] SWAP :  Replace the lable of incomming packet
3] POP    :  Remove the lable from outgoing packet and also aka Lable disposition.