API vs SDK -
What’s the Big

Application Programming Interfaces (APIs) and Software Development Kits (SDKs) both have totally different roles in the software development process. Since there are lots of overlap between the two, it can be confusing to understand the difference. Knowing how an API and SDK differ from each other and function can help you decide which one you will need for your project.

What’s an API?

First of all, APIs are all about communication. There are a set of definitions and protocols for apps or services to talk to other apps or services. and, say, this cloud-based visual recognition service.

So, what does “API” stand for in any way in development?

It’s “Application Programming Interface” – A.P.I.

And what are some of the aspects of APIs that make them useful?

  • Communication: So, communicating between a service and another service, an app, and another app, API allows your application to interact with an external service or services using the simplest set of commands. To break down the name, the “Interface” is where different software components and tools can interact. Using an API allows developers to add specific functionalities to their applications which are very helpful and can speed up the development process. Know you understand how they talk to each other.
  • Abstraction: What does “abstraction” mean in APIs?
    So, inside the VR service, up in the cloud, there’s probably potentially thousands of lines of code running up there, And you as a developer of a mobile app you don’t want to have to worry about, which method in this service do I call to get the “required data”?”

    You don’t want to have to worry about that. So, what an API does is it abstracts away all that complicated logic and you just have to worry about getting just the data you need. It simplifies the process.
  • Standardized: APIs are standardized. Meaning, there are industry-defined standards for how to define an API and there are a few formats that are popular for APIs.

    You may have heard of SOAP, GraphQL, or REST stands for “Representational State  Transfer”,

What are some of the building blocks of APIs?

First of all, to actually send data, or send what’s called a “request”
from the mobile app to the VR service on the cloud you need to have a few different pieces. So, for a REST API call request, you need to have what’s called an operation. That could be HTTP methods like POST, PUT, GET, DELETE.

All of these APIs act like building blocks, allowing developers to build applications much faster. They also prevent developers from having to “reinvent the wheel,” and spend time creating functionality that already exists.


  • Libraries and frameworks
  • Operating systems
  • Remote APIs
  • Web APIs


The idea of the API is much older than the term. British computer scientists Wilkes and Wheeler worked on modular software libraries in the 1940s for the EDSAC computer. Joshua Bloch claims that Wilkes and Wheeler “latently invented” the API because it is more of a concept that is discovered than invented.

This observation leads to APIs that supported all types of programming, not just application programming. By 1990, the API was defined simply as “a set of services available to a programmer for performing certain tasks” by technologist Carl Malamud.


What’s an SDK?

An SDK stands for “Software Development Kit” S.D.K. is a set of guidelines, tools, and programs used to develop applications for a specific platform. As suggested by the name, an SDK is a kit for developing software. SDKs can include APIs (or multiple APIs), IDE’s, Tools, Documentation, Libraries, Code Samples, and other utilities. SDKs boast a set of robust features and functionalities which reduce the complexity of developing programs and applications.

They facilitate the creation of applications by having a compiler, debugger, and perhaps a software framework. They are normally specific to a hardware platform and operating system combination.

So, we came to know that all SDKs, you can really think of like a toolbox of tools, or code that actually call APIs for you. So, you may be specialized in one programming language over the other, you know, there are SDKs in a variety of languages. So, there’s maybe an SDK in Java, in Node, in Dart(Flutter), or Python -whichever language that is your specialty there’s probably an SDK for you.

Why do we need SDK?

SDKs are designed to be used for specific platforms or programming languages for software developers. Thus you would need an Android SDK toolkit to build an Android app, an iOS SDK to build an iOS app, a VMware SDK for integrating with the VMware platform, or a Nordic SDK for building Bluetooth or wireless products, and so on.

To create applications with advanced functionalities such as advertisements, push notifications, etc; most application software developers use specific software development kits.

Why are SDKs important?

Without an SDK, a lot of this pre-built functionality would have to be made from scratch. SDKs not only let you create new tools efficiently but also make the process easier for everyone involved because everything is pre-built. New features just need to be made compatible with the current system.

The Characteristics of a Good SDK

SDK has to provide value to other businesses and their developers. That value is dependent on your SDK having the following characteristics:

  • Easy to use by other developers
  • Thorough documentation to explain how your code works
  • Enough functionality so it adds value to other apps
  • Does not negatively impact a mobile device’s CPU, battery, or data consumption
  • Plays well with other SDKs

In short, it just has to work. Ideally, it should work elegantly, but when time is of the essence, as long as it gets the job done, it should be good enough.


Some very popular examples of software development kits are the Java development kit (JDK), the Windows 7 SDK, the MacOs X SDK, and the iPhone SDK.

Some SDKs are required for developing a platform-specific app. For example, the development of an Android app on the Java platform requires a Java Development Kit. For iOS applications (apps) the iOS SDK is required. For Universal Windows Platform, the .NET Framework SDK might be used. There are also SDKs that add additional features and can be installed in apps to provide analytics, data about application activity, and monetization options. Some prominent creators of these types of SDKs include Google, Smaato, InMobi, and Facebook.

Comparison of API vs SDK





Connects and integrates software   

Contains a variety of development  tools


Lightweight, fast, usually specialized  

More robust, usually includes many utilities

Use Case

Used for adding specific functions to an application

Used for creating new applications or adding many functionalities with one package



APIs and SDKs are similar, but both have distinct characteristics and advantages. Understanding the differences can help you choose or select which is best for your project. Review the chart above for a reminder of the key differences between an API vs SDK.