404Not Found

服务器无法找到所请求的资源。返回该响应的链接通常称为坏链（broken link）或死链（dead link）

The origin server did not find a current representation for the target resource or is not willing to disclose that one exists.

A 404 status code does not indicate whether this lack of representation is temporary or permanent; the 410 Gone status code is preferred over 404 if the origin server knows, presumably through some configurable means, that the condition is likely to be permanent.

A 404 response is cacheable by default; i.e., unless otherwise indicated by the method definition or explicit cache controls¹.

• ¹ Calculating Heuristic Freshness RFC7234 Section 4.2.2
• Source: RFC7231 6.5.4