What is an API?
API is the acronym for “Application Programming Interface” – a set of rules and definitions that allows software applications to communicate with each other.
Like a user interface allows a human user to communicate with a computer, an application programming interface connects computers to each other without human interaction.
An API can be described as a kind of “messenger” that requests data from a server and delivers the response back to the application.
What is API Integration?
When people mention APIs, they are usually talking about web services.
Every web service is an API, but not every API is a web service.
An API integration is the connection between two or more systems or applications via their APIs, that enables those systems to exchange data.
Types of API Protocols
- SOAP (Simple Object Access Protocol) is an API protocol that uses XML that sends and receives data through SMTP and HTTP. SOAP APIs are ideal for sharing information between apps or software, independent of their environment or language. SOAP provides a high level of security and is frequently used for payment gateways, financial services and identity management. However, as it only uses XML it is verbose and requires more bandwidth than other formats.
- REST (Representational State Transfer) is a set of web API architecture principles, as opposed to a protocol like SOAP, with a certain number of architectural constraints. Web APIs that comply with these architectural constraints are called RESTful APIs, although most of the APIs referred to as “RESTful” don’t fully meet the standards for REST architecture and are actually just “HTTP interfaces”. RESTful systems support messaging in different formats, such as plain text, HTML, YAML, XML, and JSON. REST is easier to use and requires less coding as it makes data available through endpoints each endpoint is represented by a unique URL.
- GraphQL is a data query syntax created by Facebook (Meta), which also serves as an API query language. GraphQL is not protocol-bound but it can utilise HTTP like REST.
One of its main advantages is that it only requires a single endpoint for fetching data.
It allows the client to define the exact data it needs from multiple sources, so only one API call to request all needed data is needed. GraphQL uses a type system to describe data.
Below is an overview of the different types of API protocols:
More and more webapps are using a technology called webhooks.
Although APIs and webhooks have a similar function, webhooks work in the other direction.
Webhooks are essentially a subscription to receive data when a particular event happens, which means that you
do not actively have to request data.
While a traditional API integration needs to pull data from a server periodically, webhooks enable the webservice to push this data over at the instant something happens. The request that a webhook makes can either contain the data required for the integration to work or prompt the integration server to make a subsequent request to get the required data.