ok so the other day l decided to climb a rope that was like 20ft high. l got to the top and then l realized l have to get down. l did not wanna just let go and drop 20 ft. that would suck. so l climbed down with my arms just like climbed down. the problem is that getting down is harder than going up. its way harder when you are using your hands and arms to stop your body from falling. so what is the correct way to climb down a rope. just curious.

Well like, if u were rock climbing you'd have a device with u called a belay plater, or a gri gri, or a figure of eight. Failing that you'd use a certain knot called an italian hitch & a biner. You'd also need a harness. If u did not have any of these there is a certain way u can pass the rope around ur body to create friction to control the speed at which u descend called the classic belay. l know acrobats at the circus loop the rope around a foot & secure it with thier other to create the friction to slow thier descent. It is called Rappeling, in the states & abseiling over in Europe.

You're right, unless ur hands r used to it, it is gonna hurt. But it is a great way to keep ur body in shape. If u have jeans on, u can wrap ur legs around the rope, & use them as a clamp. If u do not have jeans on, do not try it, u will rub ur legs up.
You also can use ur shoes. Depending on ur foot dexterity, u can grip the rope with the sides of ur shoes or even do the frog leg thing & grip the rope with the flat of ur feet. But u will really have to be flexible for that.

Unless you're wearing a harness, getting down a long (20ft is not much) stretch of rope can be daunting indeed.

One way of doing it without equipment is to wrap part of the line starting at ur shoulders & going downwards to the hip, in a '' kind of fashion, then making a loop around ur thigh, & a similar one around ur extended arm.

Sliding down will involve an amount of friction taken up by the back, thigh & ur arm. Make sure the loops r equally loaded. You will have a scar/mark if u release too much of the rope at one time. Useful only in emergencies or for short, quick rappels.

Wear gloves