Definition - What does Extensible mean?
Extensibility is a measurement of a piece of technology’s capacity to append additional elements and features to its existing structure. A software program, for example, is considered extensible when its operations may be augmented with add-ons and plugins. Extensible programming languages have the ability to define new features and introduce new functionality within them.
Techopedia explains Extensible
The concept of extensibility has existed since at least 1960, during which computer scientists and programmers like Douglas McIlroy and Tony Brooker posited ideas about programming languages and software whose features could grow and be expanded upon through time. The idea was further solidified in 1969 at the Extensible Languages Symposium, where Carlos Christensen outlined the idea of a programming language that could be extended with “meta-language” with the ability to “expand, contract, or otherwise modify the definition of the base language.”