Simple definition
The HTTP HEAD method retrieves response headers equivalent to GET without transferring the response body.
Purpose and use
HEAD obtains information corresponding to a GET response without transferring the representation content.
How does it work?
The server returns status and control or metadata fields; selected fields calculated only while generating content may be omitted.
Example and verification
HEAD can provide lightweight availability or metadata checks when its behavior is compared with GET on the relevant service.
Points to watch
A successful HEAD response does not prove that GET can correctly generate or transfer the complete body.
In short
HEAD avoids transferring content but does not replace functional validation of the actual resource.