Rebuilt Head. What does it mean exactly?

Hello. I'm looking to buy a 2000 4 Cylinder 5 speed that has a rebuilt head. What exactly does it mean and is it risky to buy a car that someone else had work done too? I'm not so familiar with mechanics so any help is appreciated. Thanks.

 

It depends on how much of it was rebuilt.

The head is where the camshafts/valves, etc..all reside.

The head could have been removed/machined, honed, valves adjusted, new seals, etc...

The important thing is to find out why the head(s) had to be rebuilt.

 

The ad says the head was rebuilt due to the truck consuming oil.