What is the Difference between SDK and API?

Learn about software development kits (SDKs) and application programming interfaces (APIs) and how they improve the software development cycle and end user experience (UX). In modern software development, SDK and API are the two main tools you will come across. They have a lot in common and sometimes get confused about their respective jobs. Both the SDK and the core API enable you to enhance the functionality of your application with relative ease. In order to fulfill the promise of one or both, and improve the experience both internally and for end users, it is important to understand how these two tools work on the back end, how they differ, and how they contribute to the overall development process.

1. What is SDK?

SDK stands for Software Development Kit. An SDK, also known as a devkit, is a set of software building tools for a specific platform, including building blocks, debuggers, and often a framework or set of code libraries, such as a set of operating system (OS)-specific routines.

A typical SDK might include some or all of these resources in its toolset:

• Compiler: Translating from a programming language to the language you will be working in

• Code example: Give a concrete example of an application or web page

• Code library (framework): Provides a shortcut to code sequences that programmers will reuse

• Testing and analysis tools: Gain insight into how an application or product performs in test and production environments

• Documentation: Provides instructions to developers that they can refer to

• Debugger: Helps teams find bugs in their code so they can roll out code that works as expected

Typically, at least one API is also included in the SDK, because without an API, applications cannot communicate and work together.

2. What is an API?

API stands for Application Programming Interface. Whether as a standalone solution or included in the SDK, the API facilitates communication between the two platforms. It does this by allowing third-party developers to take advantage of its proprietary software. Developers can then let their own users indirectly consume the services provided by the API solution.

You can also think of an API as a kind of agreement between two parties. An API not only allows information to be exchanged on demand, it also specifies how information should be exchanged.

Because some APIs directly provide interfaces, the terms "API" and "interface" are sometimes used interchangeably.

Breaking it down, an API can consist of two parts:

• Technical Specifications and Documentation: This information explains how to integrate the API to use it effectively.

• The interface itself: you can access it directly (in the case of a web API) via a keyword, or indirectly from a separate interface (in the case of a REST API).

Some popular APIs include:

• Web APIs for accessing web browsers and devices, or applications as their own web services.

• SOAP APIs, which are a popular choice in cases of increased data privacy and security.

• Open API (or public API) and REST (or RESTful) API, which are popular choices for ease of use and maximizing bandwidth.

• JSON-RPC, the best choice when asynchronous server calls are required.

• Custom APIs to maximize software development flexibility.