A unique click is a click associated with a single Internet Protocol (IP) address or computer.
This means that no matter how many times a user clicks on your ads, it will only be registered once as a unique click. This is especially important to prevent fraudulent activity.
For obvious reasons, unique clicks are much more valuable than gross clicks or hits.
To learn more about the differences between various click types, read this:
What is the difference between gross clicks and clicks
In CrakRevenue, a click is equal to a unique. Indeed, regardless of the number of clicks the user makes on various offers, the user will always be considered unique. Therefore, the EPC calculation in CR tends to be a little higher since less clicks are interpreted when compared to other platforms.
On the other hand, the notion of gross clicks is only based on the action of clicks. Therefore, the gross clicks will show the total amount of clicks even if they are made only by a unique user.
In other words, if the same users click 5 times on the same offer/banner, it will show 5 clicks in the GROSS CLICK column and 1 click in the CLICK column. This tends to dilute the EPC value.