$EVThe EV, expected value or chip-EV is the average number of chips you can expect as the result of an action. The EV simply tells you: What is the average number of chips I will have gained or lost at the end of this action?
The $EV, which is important for the ICM, is the monetary equivalent of the EV. Since you don't convert your chips to money in a tournament, but try to rank as high as possible, the $EV helps you with the question: How will this action affect my expected value and my place in the ranking?
Important: Since there is no linear correlation between the EV and the $EV (i.e. double the EV does not equal double the $EV), there are actions that are +EV, but -$EV. You should avoid such actions, since it is always your goal to maximise the $EV.