Some have different scents, others are for different kinds of loads... It's complicated, so you can learn it later.

[ it's too advanced for kenta right now!! also, he just assumes Rich People have dryers by default... ]

When the washer finishes washing your clothes, they're going to be clean, but soggy — so you toss them in the dryer next. Adding a dryer sheet is optional, but they make your clothes feel softer and smell nice afterwards. I recommend it, but it's up to you.