Having a puppy, and later on a dog, that will stay will be very useful for you in everyday life. There will be times you will need your dog to stay in a specific spot for short periods.
A sit stay is when the puppy sits on cue and stays in position when asked. Sit stays will be useful when you want to get in or out of the front or back door, load or unload your car, go through a gate or see visitors off in the drive way.
A drop stay means asking your dog to "drop" so he is lying on the ground and then to "stay" in the drop position. Drop stays can be very beneficial around active, excited children or around other dogs that might be fearful or non social.
At other times you may ask you puppy to "stay" in a standing position. Stand stays will be very useful for veterinary examinations and grooming sessions.