Utilizes the Replace-By-Fee mechanism to replace an existing unconfirmed transaction with a new one with a higher fee.

How is this used?

Imagine sending a letter and realizing you've shorted on postage, causing it to linger at the post office. In the same vein, the 'bumpfee' command is your solution for a Bitcoin transaction that's dragging due to an insufficient fee. Much like the post office sorts mail by postage value, Bitcoin miners give precedence to transactions with higher fees. If your transaction is stuck during peak network times because of a low fee, employing 'bumpfee' is akin to paying that extra postage, ensuring your digital 'letter' is prioritized and processed quicker.