API stands for Application-Programming Interface. It is a technology that creates a bridge between two systems and allows them to interact with each other. There are two types of APIs in general, push and pull. For example; an organization uses an HRMS solution for HR and Payroll activities but another accounting system for accounting activities, in this case, financial data need to communicate with each other to give desired results.  The API of the HR system pushes the financial data to the accounting software. Like this, HR APIs can be used in collaboration with various other systems. It is a common method to integrate with an external system.