Origami bases are sequences of folds which are used over and over again in different origami models. Instead of describing the same steps over and over again, an origami author or creator might just say, “Start with Waterbomb Base” and then expect that you know what a Waterbomb Base is.
Different origami books will have different bases which are related to the models found in that particular book. So, there could be many, many different bases. However, there only a handful of origami bases are universally accepted by all origami enthusiasts. These include:
In other countries, origami bases may have different names, but one look at the sequence of folds will tell you that they are one and the same.