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