To reduce the bandwidth used by web traffic HTTP was extended to make it possible to make more than one request within a single connection. This is called a persistent connection, or that it is kept alive.
If enabled, allow browsers to establish persistent connections. If it is disabled the web server only accept one access per connection.
The number of seconds to wait for the next request in a persistent connection. If it is exceeded the connection is closed.
The maximum number of requests allowed in a persistent connection.