"The pocket" in music is probably as difficult to explain as CTE
It's a feel. Even with the click, there is a pocket that can be found, tho not always, nor required. The style of music helps determine how important it is.
A "hook" is also difficult to explain, tho not as tough as "pocket". The hook is the part of the song that "hooks" you, that catches your attention, or is more easily remembered. It can be the chorus but can just as frequently can be an instrumental portion of the song. A guitar line, or a bass line, will often be what grabs you in any given song. Again, they style of music can dictate whether or not you might have noticeable hooks.
<----weekend warrior in bars all around here, been playing drums for 45 years