A 410 looks similar to a 404 from a visitor's side, both mean the page isn't there, but it carries a more deliberate message: this content was removed on purpose and isn't coming back, rather than simply being missing right now. A 404 leaves the door open; a 410 closes it.
Search engines treat that distinction as useful information. A 404 can leave a search engine checking back periodically in case the page returns, while a 410 tends to get a URL dropped from the index faster, since the signal is explicit rather than ambiguous. That makes 410 the more accurate code for a product that's been discontinued for good, an event page well past its date, or content deliberately retired rather than accidentally lost. Using it correctly instead of defaulting to 404 everywhere helps search engines clean up their index of a site more efficiently.
