Public and private APIs
Public APIs are, surprisingly, only the small part of the whole range of APIs for e-commerce (even though public APIs are the most popular because they are used by everyone up to a few hundred times a day per person). Their purpose can be almost anything, such as a social network update, weather broadcast check, and so on.
Private APIs, on the other hand, are much more business-oriented. They are created for customers (paid customers mostly) by developers and their goals are partnerships, productivity and other e-commerce API design benefits.
Web APIs themselves can be further separated based on the architecture, this won’t be explained in too much detail in this article. The most important thing to know is that the most popular one is probably REST (Representational State Transfer) – a set of principles that many developers follow in their work. In addition, there is also SOAP (Simple Object Access Protocol), JSON-RPC, XML-RPC and others, each with their own use cases, strengths and weaknesses.