Can you help me?

I'd be glad to help you

The first correction:

what does ( "does" would be the incorrect word to use here, it should be "is" instead, also adding "the" after "is". So the correct sentence would be "what is the difference between")

Now the second partof my corrections:

difference between "in the end of the month" and "at the and of the month"?
thanks

( You wouldn't say "in the end of the month" in means to indicate inclusion in a space or place; while at means to indicate a postion or location in time. So it doesn't make sense to say "in the end of the month" you see? You would just say "at the end of the month")

Examples:

→Her birthday is at the end of the month.

→My appointment is at the end of the month. 

 But if you dropped "of the month" it would be correct to use either "in" or "at".

Example:

→Correct: In the end, she was all he had left.

You could also use "at" for this sentence.

But if you were to add "of the day" to specify a place in time, using "in" would be incorrect.

Example:

→Incorrect: In the end of the day, she was all he had left.

→Correct: At the end of the day, she was all he had left.

I hope my explanation helped you, I'm no teacher but hopefully you understand the difference now.