Let us consider that we have an AltCoin named ABCCoin, ABC. I will be referred to as X, mined a block and got a freshly minted 25 ABC as a mining reward. Now, I want to gift this coin to a friend Y. So,
Tx: X -> Y : 25ABC
And let us assume that this was stored in block B100. Now after some months, Ms Y wants to transfer it to Z for any reason. So,
Tx: Y -> Z : 25ABC
Now, a few months later. Mr Z wanted to buy a coffee in Starbucks while going on a date with his girlfriend.
Now the chain of transcation will be as below:
|Tx|Minted -> X | --> "Tx: X -> Y : 25ABC" --> "Tx: Y -> Z : 25ABC" --> "Tx: Z -> Starbucks : 25ABC"
So, in this situation. When we need to verify "Tx: Z -> Starbucks: 25ABC" do we have to trace it back the origin, i.e. to the point when this coin was minted OR can it be just verified just by checking its immediate source. i.e. "Tx: X -> Y : 25ABC" and dont care about other previous.