Ok maybe not the last one (Which is a key on your keyboard.) .. but caps on stats can be confusing.
Hard caps on stats used to be more prevalent, but they still exist. A hard cap is a value beyond which no improvement occurs. If you have power with a hard cap of 100, 1 million power gets you the same effect as that original 100.
What is hard capped in Neverwinter?
This leads to talk of 'diminishing returns', curves, and fancy formulas. Its not necessary to get into all that, as long as you realize that whatever the soft cap is, adding beyond that gets expensive and doesn't do you very much good. You're most often better off improving other stats after that point. There are very few exceptions, but you really have to know what you're doing to get the balance right in those cases.
What is soft capped in Neverwinter?
One thing that may add to the confusion must still be mentioned however. If you are at the soft cap for something like combat advantage there can be differences between things that say something like "adds 100 to combat advantage" and those that say "adds 5% to combat advantage". In many cases the 2nd one will still help. Further research will need to be done on your specific item.
EDITED: Removed regeneration and movement from the list of soft capped stats. Though rarely fully discussed, it appears that these are not actually soft capped.