SEO — Search Engine Optimization
SEO is the practice of making a website more likely to appear, and rank well, in search engine results (Google, Bing, and similar). It covers things like using the words people actually search for, having a fast and mobile-friendly site, writing genuinely useful content, and earning links from other sites. SEO is a long-term, ongoing discipline — not a setting you turn on once.
"Save" — just saving a file
This one isn't a business term at all — it's the everyday action of saving a document, image, or file so the changes aren't lost. It gets confused with "SEO" mostly by sound and context (both come up constantly around websites and files), but they have nothing to do with each other. If someone says "did you save it?" they mean the file on disk, not search rankings.
CEO — Chief Executive Officer
A CEO is a person — the most senior executive responsible for the overall direction and decisions of a company. It has no technical meaning related to websites at all. The confusion here is purely phonetic: "SEO" and "CEO" are the same three sounds in a different order, which is exactly why they get swapped in fast speech, especially across languages.
Why bother clarifying this
Because it changes who you ask for what. A question about visibility in Google goes to whoever handles SEO. A question about a missing file goes to whoever was editing it last. A question about company direction goes to leadership. Three completely different problems, one unfortunate coincidence of sound.