Are attack rolls and saving throws basically specialized ability checks? They aren’t.

Are saving throws ability checks DND 5e?

So while saving throws and attack rolls are based on your ability scores, they are not ability checks.

Do ability checks count as actions?

Some ability checks are actions, some aren’t. Many are, but it’s not a blanket rule. Sometimes a character does something as a part of their movement, which requires no action, and the DM decides (or the rules suggest) that it requires the character to make an ability check.

Skill checks are a subsection of ability checks.