An applet (little application) is a small software program that supports a larger application program. In the past, the term applet was often associated with the Java programming language.
An application program interface (API) is code that allows two software programs to communicate with each other.
A data source object (DSO) is a Microsoft ActiveX object embedded within a Web page. It employs a process called data binding, in which an ActiveX control communicates directly with another Web page, or with an external XML data source.
Enterprise application integration (EAI) is the task of uniting the databases and workflows associated with business applications to ensure that the business uses the information consistently and that changes to core business data made by one application are correctly reflected in others.
Microservices, or microservice architecture, is an approach to application development in which a large application is built as a suite of modular components or services.
An open API, also known as a public API, is an application programming interface that allows the owner of a network-accessible service to give universal access to consumers of that service, such as developers.