Years ago we called it 'paper training'. While some people still use paper, we now have a variety of absorbant pads with a moisture proof backing. They go by a variety of names including 'potty pads' and 'wee wee pads'. The purpose is the same, a designated toilet spot for your dog. The potty pads are superior to paper (usually newspaper) for several reasons; they are more absorbent, won't get newsprint on your dog's feet, and you won't have your pup peeing on the Sunday edition you left on the floor by accident. There are situations where having your dog trained to use a potty pad can be a good thing: You live in an urban area with regular inclement weather. You have health or mobility issues that make regular trips outdoors difficult. You live in a high rise apartment so a trip to the street takes several minutes. You travel frequently with your dog. You work odd hours and aren't always able to let your dog out at reasonable intervals.Unfortunately, potty pad training may cause you more problems than it solves. For many puppies, being permitted (and expected) to use potty pads in the house tells them that it is okay to potty in the house. This is very confusing to many dogs. The pads are most often used for smaller breed dogs and many of these breeds have a reputation for being difficult to house train. Perhaps the potty pads are part of the problem. Even if the pup is regularly using the pads, if the location of the pad remains the same, the pup may associate 'toilet area' with the location and not just the pad. So you move the pad and the pup keeps peeing the old spot.
Once the puppy is no longer tiny, or the weather outside has improved, or the owner is tired of picking up dirty pads, they decide they now want the pup to eliminate only outside. This is where things can get ugly. The person has changed the rules on the pup and the puppy gets very confused. The pup won't potty outside, waits to come inside and pees on the floor, the owner gets more and more frustrated, and the pup runs the risk of being sent off to the shelter. It's NOT the puppy's fault that her humans changed their mind.
If your long term plan is for the dog to only eliminate outside, then I suggest skipping the pads and going straight to work teaching the pup to potty outside... in all kinds of weather. If your life is such that having the potty pad option available for the pup is a good idea, then your training will be a little more involved and require extra patience and persistence. You CAN teach the pup to use the pads and to go outside, but you may need some help from a positive trainer.
If your pup already uses pads and you would like to eliminate them, you need a 4-6 week plan for gradually phasing out the pads and teaching the pup the new routine. This starts by moving the pads a few inches toward the outside door each day. When the pad is beside the door, you introduce the bell at the door so the pup can signal you that she needs to go out. Then the pad gets moved to just outside the door and you make extra efforts to supervise and take her to the door on a regular schedule. Ask the pup to ring the bell to gain access to her pad. Give lots of praise and encouragement at this stage because the pup is making a leap of faith. When she starts ringing the bell on her own to ask you to open the door, you can move on to the next stage. Start moving the pads farther from the door on the outside until they end up in the location you want your dog to potty. Then slowly reduce the size of the pad until the pad 'disappears' and your pup is now going potty in the yard without any pads.
Congratulations! Your puppy has now learned to ask to go outside and the pads are gone. Since she originally learned to use the pads, you should still be able to use them in a pinch (illness, travel, weather), but your pup is now house trained :-)