Blockchain networks are often described as permanent and unchangeable, but that does not mean the software running them stays the same forever. Like any complex technology, blockchains need to evolve. Developers discover bugs, new security techniques emerge, users demand better performance, and communities propose new features.

When you send cryptocurrency, the transaction usually does not appear in a confirmed block immediately. Between clicking “send” and seeing a confirmation, there is often an important intermediate stage: the transaction mempool.

If you've ever sent cryptocurrency from one wallet to another, you've probably wondered what actually happens after you click "Send." While the process may seem instant from the user's perspective, a blockchain transaction goes through several important steps before it becomes a permanent part of the blockchain.