HTTP/2 is the newest version of the HTTP protocol, based off SPDY. Its development was initiated by Google and HTTP/2 is largely based on the codebase and concepts of SPDY.
SPDY has now been deprecated and worldwide adoption for HTTP/2 is in progress. Many hosting companies have already provided support for HTTP/2 due to its added speed.
At the time of writing, DirectAdmin does not provide a one-click way to enable HTTP/2. However, there are multiple ways to achieve HTTP/2 support. The method outlined below has proven to be the most robust and stable approach.