A Bit about APIs

If you’re not a developer, then API probably doesn’t mean much to you, and Developers will appear to be talking to each other in code, “we’ll get that info via a restful call to the API endpoint, or perhaps via SOAP?”.

Gobbledegook right? So what does it all mean?

An API is the way that a system allows other systems to interact with it. API is an acronym for Application Programming Interface. You’ll hear several acronyms mentioned when talking about APIs such as SOAP, XML, JSON, ReST and WSDL. Common ways that systems interact over the internet are via SOAP or REST.

Here’s a little about both;

• SOAP (Simple Object Access Protocol) is predominantly associated with Microsoft .Net systems. SOAP uses a WSDL (Web Service Definition Language) file, which sets out the structure of how the data is passed to and from the system.
• ReST (Representational State Transfer), commonly referred to as ReSTful, is a means of creating, reading, updating or deleting data in a remote system known as CRUD. The remote “client” system is entirely separate from the “Server” and the relationship between the two is said to be stateless. 

Data received across HTTP using an API is usually in the format of XML or JSON:

• XML is an acronym of eXtensible Markup language and looks a lot like HTML and describes the data contained absolutely. 
• JSON is an acronym for JavaScript Object Notation. It is most commonly associated with ReSTful APIs and contains name/value pairs that describe and deliver the information.

API’s are used throughout web and app development. We may use an API to send an email using an SMTP API call to a remote mail server, ask Google’s API to give us the distance between two postcodes via road, get the latest news from a WordPress site or interact with your CRM to streamline your business. Or even something as simple as getting the time. 

To summarise, an API is a way of one system speaking with another using as little or only the information that is required for the application or function to work.

Whether using SOAP or ReSTful APIs, the beauty is as long as you adhere to the rules of how the remote system expects you to ask the question of it. The answer will be provided in a format that you can process in whatever application you wish.