An API, or Application Programming Interface, is a set of rules and protocols that allows software applications to communicate and exchange data with each other.
An API can be seen as a layer, or portal, between the different systems. This is how different applications and software components integrate with each other and work together as a fine-tuned system. APIs are fundamental to how software is developed today. It enables developers to build applications that use the capabilities of other systems and so making their own software more powerful for end users.
Examples of where APIs are used Today, APIs are used prolifically, especially in mobile and web applications. Just a few examples that you would come across everyday include weather apps, banking apps and payment gateways like PayPal. Every time you use Google Maps, there is an API working.
You get APIs that are free for anyone to use - public APIs - such as the Facebook API. Alternatively, you also have private APIs which are only accessible to authorised users who use them for internal systems or to connect with partner systems.
Some Key Points about How APIs Work
Interoperability APIs are like a common language that different computer programs use to communicate with each other, even if they're made by different developers and run on different platforms. By connecting different parts you can create complex systems.
Abstraction Layer This means that developers can use an API to interact with a system without needing to understand all the intricacies of how that system or service works internally. It's like driving a car without having to be a mechanic.
Functionality APIs can do a wide range of different things, like getting information, changing data, or controlling hardware. For example, social media apps let other programs use their APIs to see your posts or do things on your behalf – think of apps like Hootsuite that allow you to post to the different social media platforms from one place.
Standardisation Many APIs follow rules and common ways of doing things, making it easier for developers to use them. It's like everyone agreeing to use the same road signs and driving rules. Common API protocols include REST (Representational State Transfer), SOAP (Simple Object Access Protocol), and GraphQL.
Security Keeping APIs secure is extremely important, especially when they deal with sensitive information. APIs use authorisation checks to make sure only the right people or programs can use them.
API Versioning APIs can change and get better over time, but this can break the programs using them. So, API developers often use version numbers to let old programs keep working while adding new features for new programs.
To learn more, see:
What is an API?
