Digital signatures, mate! They're a crucial part of how Bitcoin works.

In simple terms, a digital signature is like an electronic fingerprint. When you send a Bitcoin transaction, your wallet uses your private key to create this unique signature for that specific transaction. This proves that the transaction came from you and hasn't been tampered with.

As for what they look like - digital signatures are just long strings of characters. Here's an example:

`3045022100eff69ef2b1bd93a66ed5219add4fb51e11a840f404876325a1e8ffe0529a2c80022015b6`

You won't usually see these in your wallet though - they kinda work behind the scenes. All you see is "I'm sending X bitcoins to address Y", but under the hood there's all this cryptographic magic happening!

And remember, no two transactions will have the same signature even if they're from the same wallet – each one is as unique as... well... a fingerprint!