Application Programming Interfaces (APIs) are constructs made available in programming languages to allow developers to create complex functionality more easily. They abstract more complex code away from you, providing some easier syntax to use in its place. Securing a REST API also starts with industry best practices, such as using hashing algorithms for password security and HTTPS for secure data transmission. An authorization framework like OAuth 2.0 (link resides outside ibm.com) can help limit the privileges of third-party applications.
For communication between these distributed systems, APIs are used. APIs are any software component that serves as an intermediary between two disconnected applications. While web services also connect applications, they require a network to do so. Where some APIs are open source, web services are typically private and only approved partners may access them.
Most business applications have to communicate with other internal and third-party applications to perform various tasks. For example, to generate monthly payslips, your internal accounts system has to share data with your customer’s banking system to automate invoicing and communicate with an internal timesheet application. RESTful APIs support this information exchange because they follow secure, reliable, and efficient software communication standards. An API is a set of definitions and protocols for building and integrating application software. Developers use APIs to make their jobs more efficient by reusing code from before and only changing the part that is relevant to the process they want to improve.
In a client-server architecture, the server handles the business logic by interacting with the databases and processing the data, whereas the client handles how to visually represent that data. APIs are used to bridge the communication gap between these two. The backend developers develop the API on the server side and send its API documentation with it’s endpoint to the frontend developers, who can use it on the client side to visualise the data. An API acts as an interface that allows proper communication between two programs whereas a web application is a network-based resource responsible for completing a single task. Also, it’s important to know that “All web services are APIs, but not all APIs are web”.
You can use it to define requests that have been made, handle business logic, the and manage data formats that should be used and the conventions to adhere to when building software products. But APIs can get pretty complex depending on the application’s code base and use cases. This means that testing your API endpoints might be a tricky process after developing them.