API stands for "Application Programming Interface". And while this might sound strange if you're new to programming, they're easy to understand once you break it down. You even use them daily while operating your mobile phone, PC, or while browsing the internet.

Software, including web apps, mobile apps, and many other programs, link the world together via the internet. But to make this more efficient, there must be a communication channel between this software—that's where an API comes in.

Here, we'll explain the meaning of APIs and how to use them.

What Is an API?

Do you know how you're able to see videos on streaming platforms like Netflix and YouTube among others? It's possible because you're sending a request through an API.

Or have you imagined how you're able to pay for the goods you buy from online stores like Amazon and eBay? That's also because there's a communication channel known as an API between your bank and the shopping apps.

That said, an API is an interface with a set of rules that allow your app's server to interact with a solution provider's server so that you can use their resources. In essence, it defines how apps or software communicate with each other.

In some cases, however, an API allows mutualistic data exchange. An example is a connection that exists between your bank apps and online store apps.

An API is like a messenger. It connects to a provider's server on one end and also anchors the client's server on the other end. It then tenders the client's request to the data source (provider's server) and returns a response to the client. A client here is the browser or your app.

A hook, however, attaches your app to the API. That's an API endpoint. However, a lot of things unfold behind the scene. We'll explain these further.

How APIs Help You Develop Apps Faster

APIs are a smarter tool for building seamless and robust applications. Without them, building sophisticated apps would take ages.

Imagine that you need your app to perform complex operations, the type that takes a ton of time and effort to build. And then someone shows up with a ready-made program that does exactly what you want, and possibly better.

But how can you connect this to your app? The provider, realizing this might give you some hard time, then told you they created a connection interface (API) that makes their code and yours integrate seamlessly.

That interface (API) connects to the server containing their code. Then it feeds you back the relevant data from the action of their script.

Of course, you don't want to bore yourself with their entire source script. Besides, most of the modern APIs now rely on standardized REST (Representational State Transfer) technology. It makes them highly scalable and easy to integrate, without you needing to worry about what's unfolding within or the state of your response or request as they're preformatted.

This article won't go further explaining REST API. Focus on the basics for now.

Plugging your code into theirs is a better idea than writing it from scratch. To do that, however, you need to hook your code up with the API that they've provided. How do you do this? That's where an API endpoint comes into the scene.

What Is an API Endpoint?

A large hook and a faded truck API endpoint

To simplify things, the providers then put up a URL to make connecting to their API seamless. Such URL is an API endpoint. With it, your app can then access their server through the API and communicate with their script directly.

So all you need to do is grab the endpoint, paste it into your code, make requests with it, customize the responses, and then, it works, and it's yours! An API endpoint, therefore, binds your app through an API to a solution or data source.

Ultimately, many of the programs that offer APIs are available in various programming languages so that no one gets excluded from benefiting from them.

That way, you get to code faster and more efficiently, knowing that the onus of maintaining the API isn't on you but the data or solution providers.

Therefore, an API endpoint is a communication hook that binds an API to a resource server at one edge and connects it with the receiver's server on the other end.

It then means you don't need the entire script of the solution you want to use. But your code can't establish communication with it if it doesn't connect to its API endpoint.

API Integration Rules

There's no hard rule for integrating an API. There is a ton of them out there, and each of them has its integration rules. But have it in mind that you're expecting a response whenever you establish a connection with an API.

How you make requests through an API endpoint is usually based on provider-defined rules, but what you do with the response you get depends on your preference. In essence, you can twist it as you like to conform with your app's users' experience and interface.

Sometimes, you also need an authenticator before you can access an API. Such authenticators usually come as access tokens or API keys. Once this token passes an authentication test, the API then signals its endpoint to establish a connection between your app and the provider's server.

As the API consumer, you need not worry about these parameters because the API provider makes them available. A great API should also state how you can access and use its resources in its documentation. So always look out for that when trying to integrate one.

To round it up, an API call is all about the headers, an endpoint, the request, and the response or the body.

While we've explained what an endpoint is, let's break down these other terms further:

Headers

Usually, you need to describe two forms of headers while connecting to an API: the request and the response headers.

The request header is the gateway of an API call. It describes a client's approach to accessing a resource. It might detail things like acceptable connection type, proxy information, and the data type (JSON, XML, or HTML) you want to get from the API.

As we described earlier, depending on the type of API you're connecting to, you might have to provide a unique authentication token within the request header as well. The provider usually gives this.

The response header, on the other hand, is an assertion of the data coming from the provider's server. It gives your app information about a provider's characteristics. In essence, it ensures that your app grants access to the response coming from the API.

API Request

An API request usually contains the endpoint in a URL (Unique Resource Locator). It uses the Hypertext Transfer Protocol (HTTP) to locate the address of the resource you're trying to access with an API. Ultimately, an API request isn't complete if you don't include the endpoint in the URL.

API Response

A response is what an API sends back each time it receives a request from your app. It can be JSON, XML, or HTML, depending on the data or content type it receives from your request header.

Once you get a response from an API, then you can consider your API call a success.

How to Use APIs: Practical Examples

Now that you know the basics of APIs and what you need to integrate one. Take a look at how to connect and integrate a football prediction API from RapidAPI using Python below.

It's a simple API call that returns a JSON response. You can also write your code in any text editor, and run it via the command line.

Related: How to Run Your Python Script

However, pay close attention to the endpoint, the content of the request headers and the response headers:

        import requests
endpoint = "https://football-prediction-api.p.rapidapi.com/api/v2/predictions"

queryparams = {"market":"classic","iso_date":"2021-01-01","federation":"UEFA"}

#Define the request header:
headers = {
    'x-rapidapi-key': "Paste your access key here",
    'x-rapidapi-host': "football-prediction-api.p.rapidapi.com"
    }

#Define the response header:
response = requests.request("GET", endpoint, headers=headers, params=queryparams)

#Get the response:
print(response.text)

Keep Learning: How to Use the IPStack API for IP Geolocation Lookups

How about getting the current temperature and humidity of a place using Weatherstack API with Python? Here's an example below:

        import requests
endpoint = 'http://api.weatherstack.com/current'
headers = {
  "access_key": "Paste your access key here",
  "query": "California"
}

req = requests.get(endpoint, headers)

res = req.json()

print(u"Current temperature in %s is %d℃" %
  (res["location"]["name"], res["current"]["temperature"]))

print(u"Current humidity in %s is %d℃" %
  (res["location"]["name"], res["current"]["humidity"]))

Types of APIs That You Can Integrate

Open-source APIs are free, and anyone can use them. Internal APIs reside within an organization, and only apps belonging to that organization can use its resources.

However, you can also opt for a dedicated API by entering a partnership agreement with a provider. Or you can combine several APIs to solve various problems.

Also, these APIs, excluding open-source and internal APIs, might come at a price, sometimes ranging from hundreds to thousands of dollars.

Simplify App Development With APIs

As you can see, that you don't need to write time-consuming code anymore. If you need your app to perform complex operations, you can always search out there and grab a relevant API. Thankfully, they're now even easy to integrate than old conventional ones. And if you're curious and want to know more, there are many free APIs out there that can help you get your hands dirty.