Pow(); This one is used to raise the power of a number. It has two parameters; the number and the power.
Pow(2,3); // This means 2 to the power of 3.
Rand(); This is used to generate a random number. It can be used without parameters, but the parameters are to set a range.
Say, I want the random number to be between 1 and 100.
Rand(1,100); Easy peasy.
