Hard Cap
The hard cap would be the absolute maximum level you can achieve, but usually has diminished returns and is not worth pursuing. The soft cap is often referred to as the level you can get to easily, or throughout the natural progression of an rpg style game. You can usually beat the game by achieving the soft cap level. Elder Scroll games are probably a good example of this.
What level is the hard cap in Skyrim?
Hard Cap
When a male awakes the morning after having sexual intercourse, also known as copulation or coitus, goes to urinate and finds a hard cap of female ejaculation incasing the head of his penis.
Stinky woke up Sunday morning with a really bad hard cap, he told me.