The response says which slice was sent.
The response status is partial content
The status row says the response carries only a selected part.
partial content
Content-Range names the slice and total
The Content-Range row says the selected span sits inside a full resource of 8 bytes.
total bytes=8
Content-Length counts the sent body
The Content-Length row says 4, matching the selected body length.
Content-Length=4
Summary
The response header tells both where the slice came from and how many bytes are sent.
Content-Range checked