Before you do either you need to decide if there is or was any information that you didn't want others to see. If you do you may want to have us security erase the drive. Just deleting the files isn't enough. An experienced computer user can recover any information that was recently deleted. We can run a special program that uses government standards to make sure none of your data is recoverable.
Trying to get rid of a phone or tablet? These are a lot more secure. Just factory reset them and they are good to go.
A printer is another item that needs some caution. If you just have a small household printer it is perfectly safe to recycle. If you have a larger office computer it is possible that it has a hard drive, that needs to be erased, or someone could get copies of everything you have printed. If you aren't sure you can check on the manufacturer's web site.