const keyword stands for constant, I see that you've made that clear already.
Now, I suggest you to get a programming book and learn it from the beginning. It has all the answers.
With const, you initialize a data variable which you don't have to (you CAN'T) change later on.
Therefore you cannot compare const int with just int.
const comes in handy when you declare something and don't have to change it later on, ie:
You wouldn't want to accidentally change the value of fiveHundredDollars, would you?
const int fiveHundredDollars = 500