API is a set of functions and procedures that allow two applications to communicate with each other.

Agile software development is an iterative and incremental approach to software development that focuses on delivering value to customers quickly and efficiently.

Responsive design is a web design approach that allows webpages to adapt to the size of the user's device or screen.

Waterfall development is a sequential software development process in which progress is seen as flowing steadily downwards through the phases of requirements analysis, design, implementation, testing, integration and maintenance.