The digital value-chain links
APIs 101 — What exactly is an API?
APIs are everywhere! But, what exactly is an API? Ask about what are APIs seems like a silly question but it is not at all. Actually, “what exactly is an API” is one of the most frequently asked questions about this topic.
If you ask a developer what is an API, chances are s(he) will explain that in a technical way. S(he) likely will say that API stands for Application Programming Interface. That is how an application or program exposes its functionalities to other applications. And that is right! People generally focus on the technical aspects of APIs. But APIs are much more than that. In fact, we can talk about API from different perspectives. We can, for example, explain “how” APIs work or — the most important in my opinion — focus on “what” value they bring.
A brief explanation about APIs
We can also talk about APIs at different levels. At the lowest level, public classes in a module are sort of like an API. This level is not important for our purposes for now. So, let’s consider that the API history starts with the need of connecting applications running in different processes. An App A needs something from App B. Then App B exposes its functionality through its API. App A doesn’t need or care to know how application B works in its internals. It is only interested in its API (facade). It is like us as consumers when we go to a baker shop. We don’t want to see the oven, we only get the bread from the counter.
After the Internet boom, what once was just called APIs become popularly known as “Web Services”. With the Internet, applications not only run on different processes but also on different machines. An application A can communicate with an application B running on in a different place on the planet.
To make all this possible, protocols like SOAP were created. Time passed and REST become more popular than SOAP. One common misconception to clarify here: SOAP and REST are not the same as APIs. SOAP and REST are high-level protocols describing how to expose an application API. An app can expose its API using REST or/and SOAP or any other protocol.
REST APIs and SOAP APIs
As said, REST and SOAP are protocols. REST APIs have become known as “Web APIs” and SOAP APIs as “Web Services”. Despite the names by which are known, both relate to “how” and not to “what”. For curiosity, AWS started by using SOAP. Some years later, AWS deprecated SOAP favoring REST. This makes me wonder if they had started nowadays, they probably would be called AWA (Amazon Web APIs) instead of AWS (Amazon Web Services) 😆.
“How” vs “What” — Talking about value
AWS provided SOAP API for its functionalities using SOAP. Then, the same functionalities were provided using REST. The most important in this case was not “how” (REST or SOAP) but the value being delivered, or “What”. Of course, how we deliver has some importance. But, in the end, what matters is the value the API brings.
As beautiful as a door looks, what is behind it is what really matters.
APIs in the real word — value chain
When we talk about APIs we can talk about the technical aspects “How” and the business aspects “What”.
One API insolated brings low value. Most parts of modern applications create value by exposing their APIs and at the same time consuming many other APIs. They aggregate pre-existent value and deliver it to the next link in the value chain in a new shape.
It is like a cascade effect. As a river flows into the sea, each link in this digital value chain adds value until reaching the end-user.
That brings us back to the initial question: What exactly is an API? Well, we have two valid answers, being the second crucial:
- APIs are how App A expose its functionalities to App B
- APIs are the links in an extensive digital value-chain
Companies like Stripe worth billions and their main product are APIs. It was not by mistake that AWS made Jassy Bezos the richest man in the world.
To know more about the APIs, I suggest visiting the page APIs Landscape. It is the result of the API Days conference where API providers and implementers can share their experiences and discuss this amazing topic ❤️.
Wrapping Up
- “What exactly is an API” is not a silly question
- We can see APIs from different angles
- People usually only focus on the technical aspects of APIs
- The value APIs bring is more important than how they are made
- SOAP and REST are not the same as APIs
- In technology, APIs are how App A expose its functionalities to App B
- In business, APIs are the links in an extensive digital value-chain
