2d platformer

This might seem like a stupid question, but how do I make platforms in a 2d platformer? do I use 3d objects or sprites? And how do I do either?

I think you should watch this:

Hi you can make platforms in 2D by creating a empty gameobjcet and adding a box collider(2D) and a sprite renderer. And remember to add a collider(2D) to the player too.

Hope it helps.