SEO is short for “search engine optimization.” It means the work people do so that a website shows up high in the list when someone types words into Google or another search engine. That work can include clear titles, pages that really answer the search, and links from other sites. It is office and tech language, not home language. In Taiwan workplaces people very often say the three letters “SEO” even when they are speaking Chinese. It is not about building the search engine itself; it is about making your page easier for that engine to put near the top. Though actually, nobody can honestly promise the number-one spot — the lists change, and the companies that run them do not publish every rule.