Hi teacher, I wanna ask some question

Firstly, The moneyness of options, I dont understand the meaning 'at-the-money, in-the-money, out-of-the-money' it is very easy to mix the concept.

Second, it very easy for me to mix the kind of the option stragegy and the model of Bull spread, butterfly spread, bear spread, calender spread ,straddle combination, combination of strip and strap and strangle combination. So i wanna simpilfy these concept and make them more easiler to understand.

Thanksa lot!