404
ELI5 — The Vibe Check
404 Not Found is the internet's most famous error — 'that thing doesn't exist.' You typed a wrong URL, asked for a deleted record, or the resource never existed. The server is shrugging at you.
Real Talk
HTTP 404 Not Found indicates the server cannot find the requested resource. It can mean the URL path doesn't exist (route not found) or the specific resource (e.g., a user with that ID) was not found in the database.
When You'll Hear This
"Return 404 when the user doesn't exist." / "The page is returning 404 — check the route."
Related Terms
400
400 Bad Request means 'you sent me garbage and I don't know what to do with it.
Endpoint
An endpoint is a specific URL that your API listens on for requests.
Route
A route is like a road sign that tells incoming requests where to go.
Status Code
An HTTP status code is the server's one-line verdict on your request. 200 means 'perfect, here's what you asked for.' 404 means 'can't find it.