What's difference between "Gas Used By Txn" and "Cumulative Gas Used" fields?

Question

I'm exploring the following transaction and don't realize What's difference between there two fields:

• Gas Used By Txn
• Cumulative Gas Used

Could you please explain. Thanks in advance

Answer 1

Gas Used By Txn - gas used by the transaction

Cumulative Gas Used - gas used by the transaction plus gas used by the transactions executed before the current one in the same block. Cumulative gas is recorded in the transaction receipt, it's described in the 4.4.1. Transaction Receipt of the yellowpaper.