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.