Skeletons are well skeletons with bows and arrows which makes them able to hit you from long range. The arrows take away about 2 hearts.

Ups: they drop arrows, which are used for bows. Bones which can be used to make bonemeal (it is used to grow crops extra fast) or tame dogs. Very rarely they drop bows. Though they have bows they have bad aim if you are moving, and it takes them a while to reload.

Downs: they shoot arrows at you from long range, and some time they are hidden making you annoyed when you randomly get hurt. They also some times where golden chest plates.

Skeletons can also spawn with armor on, and the closer you get, the faster they fire. They also burn in sunlight, but not while its raining or when they are in water. They make weird bone clunking sounds.