What does the "404 Not Found" status code mean, and how can it be used for error handling?

• 404 Not Found indicates the requested resource does not exist.
• Use it when a client requests an invalid ID or non-existent resource.
• Helps clients gracefully handle missing data.

Example in ASP.NET Core:

var user = dbContext.Users.Find(id);
if (user == null)
{
return NotFound(new { status = 404, error = "User not found" });
}