Bitcoin is an open source project, so anyone can submit changes to the protocol via a Bitcoin Improvement Proposal, or simply BIP. BIPs are numbered, and each BIP represents a proposed change to the bitcoin protocol.
When it comes to creating and backing up your wallet, Blockchain uses the current industry standard. Our wallet implements BIP44 to generate accounts and addresses, and BIP39 to generate the recovery mnemonic phrase (or seed, as it is also called). The mnemonic phrase generated in your Blockchain wallet is compatible with other bitcoin wallets that implement BIP44/BIP39. Because of the way these BIPs work you only need to backup your wallet once. Once the wallet is backed up it is backed up forever, regardless of how many funds you send or receive over time.
If you are interested in learning more about each of these BIPs then we encourage you to read the formal documentation available on Github: