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What is an API?

Learn what an API is.

In our increasingly connected world, how does data get from one place to another? Many of the tasks you perform online on a daily basis rely on sending and receiving information between different sites or services. These requests and responses are all possible thanks to application programming interfaces or APIs.

Watch the video to find out how APIs work.

APIs have been a longstanding concept in applications development. Originally, APIs were used to connect components running on the same machine. With the rise of computer networks and connected devices, more and more APIs have become available.

From government bodies to private corporations, these ‘vendors’ are increasingly providing outward-facing APIs that can be accessed over the internet. These APIs allow you to write code that interacts with a vendor’s system, or retrieve information and incorporate the response in your own applications. This process is known as API integration.

Some vendors provide ‘open’ access to their APIs, allowing anyone to connect and request information. Others require special permissions, or a fee, to gain access.

See also

Before moving on, let’s look at an article and a few videos to learn some more about APIs.

The following article is written by MuleSoft. This company was formed in 2006 and is a leading integration/API platform, based in California in the USA.

Now have a look at the following videos created by ProgrammableWeb, a news source owned by MuleSoft that covers all things API:

Now that we have covered common architectural patterns as well as APIs, it is time to check your knowledge.


  1. MuleSoft LLC. API development best practices [Article] 2020. Available from:
  2. APIs 101: What Exactly is an API? Part 1 [Video]. ProgrammableWeb; 2017 Jul 7. Available from:
  3. APIs 101: What Exactly is an API? Part 2 [Video]. ProgrammableWeb; 2017 Jul 7. Available from:
  4. APIs 101: How Does API Flexibility Help Me? Part 3 [Video]. ProgrammableWeb; 2017 Jul 7. Available from:
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