Keep Alive Header
In plain terms
A setting that reuses one connection for multiple requests.
Going deeper
The Keep-Alive mechanism keeps a TCP connection open so several HTTP requests reuse it, avoiding repeated handshakes. It saves connection overhead.
Under the hood
Persistent connections cut latency; HTTP/2 multiplexes many requests over one connection by default.
Examples
HTTP performance, connection reuse, persistent connections, HTTP/1.1.
Think of it like...
Like keeping a phone line open for several questions instead of redialing each time.