The terms laser engraving, laser etching, and laser marking are commonly used interchangeably. They are similar in the fact that a beam of light is amplified and concentrated at a single focal point. The surface of the metal is heated and its surface is altered. But where they differ is depth of penetration into the metal.
Bitcoin Improvement Proposals or BIPs are design features, inputs, ideas, information, and changes for essentially how Bitcoin works. Topics can vary to virtually anything (including wallets). They are proposed to the Bitcoin community (users, miners, developers, businesses, investors, etc.) in a concise but detailed technical document
Metal isn't for everyone. Writing your wallet seed on paper can be just as safe, secure, and effective. But keep this in mind: The biggest threat to writing your wallet recovery seed on paper is not necessarily from a fire. The biggest threat may come from: what your seed was written on, what was it written with, and how it was stored.
Your 12-24 recovery seed phrase most likely comes from the Bitcoin Improvement Proposal: 39 (BIP 39). BIP 39 is the use of a mnemonic phrase -- a group of easy to remember words -- to serve as your back up recovery in the event your wallet becomes compromised. These words are pulled from a specific list of 2048 words. In this list, the first 4 letters are unique to each word.