Initialize your variables means to declare them and then set them. You can do this all in one step. In C++, initializing variables prevents a variable from starting out with garbage and it's a good practice to get into (because they are often a source of bugs).
int x; // uninitialized variable it's anyone's guess what its starting value will be.
int y = 0; variable declared and initialized to 0
So if I want the variable to be something the user enters, how do I initialize it?