Let's start back to front
Physwiz:
And what is a fricking code tag? Iām a newbie, remember??
That's why there is a big fat sticky at the top of each board called How to use the forum. 
And some examples to hopefully answer your question
int foo; //(declaration of an) int
int bar[10]; //(declaration of an) array of int, size 10
bar[4]; //(use of the) entry of an array with type int
//which is the same type as simply 'foo' :)
Aka, same as real life
You have a single cow (in code 'cow duke')
You have a group of 10 cows called stableA (in code 'cow stableA[10]')
And the 5th cow in stableA is still just a cow (in code 'stableA[4]')