Whether or not you’ve worked with one in the past, it’s safe to assume that at least one application you’ve used was built using a Software Development Kit. Software developers use SDKs to create programs for specific platforms.
SDKs are an essential part of modern software development. In this guide, we’re going to discuss what SDKs are, why they are used and what licenses apply to SDKs.
What is an SDK?
An SDK is a package of tools used by developers to create applications for a specific platform or application. SDK stands for Software Development Kit.
Let’s say you want to develop an application for an Apple device. It would be very time consuming if you were required to write code for every part of the iPhone with which you want to interact.
That’s why Apple has their own iOS SDK. This SDK provides all the tools you need to build software for an iOS device.
The iOS SDK covers everything from handling images to networking or storing data. All these actions are crucial in many applications. By offering an SDK, Apple is able to provide a better experience to developers designing applications for their platforms.
What Can You Find in a Software Development Kit?
SDKs are like kits for building a model car or plane; there are different kits for different models. In the context of SDKs, this means the content of an SDK will vary depending on the device for which you are developing an application.
For example, the Windows 10 SDK provides tools, compilers, libraries and code samples for developers who want to work with the Windows 10 operating system. The macOS SDK may offer similar features – like code for working with device drivers, for instance – but it will be written to help developers interact with macOS. The programming languages are different and the way in which these two systems were built is different.
There are a few components you can expect in a good SDK, including:
- An Application Programming Interface: This allows you to connect your software projects to different systems and web resources.
- Documentation: Documentation may include code snippets, manuals or guides to help you understand how to make the best use of an SDK.
- Technical Components: These are the code libraries, software packages, Integrated Development Environments, debuggers and other technical tools you’ll need to develop an application. Other technical components include editors, drivers and network protocols.
SDKs can also contain other components such as visual editors. Again, what features you’ll have access to depends on the platform for which you are developing.
What Are Web SDKs?
Some SDKs are written by companies who offer web services. Twilio, the company that makes it easy to send SMS messages and phone calls from your applications, offers a range of SDKs to people who develop on their platform.
The principle of a web SDK is the same: it’s a way to enhance the developer experience. What you’ll find in a web SDK is also similar to that of a regular SDK. You’ll find examples of code, and the functions and libraries you need to work with a particular web service.
Many web SDKs are language specific and companies usually offer more than one. The Twilio SDK library, for instance, includes SDKs for C#, Java, PHP, Python and Ruby, among other programming languages. Even though they are implemented differently, each of these SDKs will allow a developer to interact with Twilio’s web services.
What Licenses Apply to SDKs?
Most SDKs are available for free. The purpose of an SDK is for a company to help people work with their services. The easier it is to use a company’s web services, the more likely a developer is to implement them into their applications.
Suppose Apple didn’t offer an SDK for their iOS devices. Developers may not have created apps for the platform because it would take too long to develop them.
Some SDKs may have restricted access. This is typical of SDKs which are in the development or beta stage and which, as a result, are not ready for public use. Most SDKs are open-source, which means you can use them freely in your applications. It’s always best to check the license which applies to a particular SDK before you start using it.
SDK vs API: A Comparison
There are a few differences between an Application Programming Interface and an SDK.
An API allows software to interact with other pieces of software. APIs are useful because they provide standard sets of instructions on how your code can work with other services on a computer.
Many websites also offer APIs which allow you to interact with their services. The Twitter API is a set of tools for building apps with Twitter services.
SDKs, on the other hand, are models for building software on top of a particular platform. SDKs are most commonly used in operating systems to provide developers with the resources they need to develop for that platform. You’ll find some SDKs developed by web services which makes it easier to use them in your applications.
Most SDKs contain APIs, which act as blueprints for working with other system services. APIs, on the other hand, don’t contain SDKs; they are open services used to interact with other pieces of software or web applications.
SDKs are used primarily to create applications and build their fundamental features, such as loading mechanisms. APIs are used to specify the functions of an application, within the limitations of a particular SDK (if one is used). Both SDKs and APIs are crucial in the creation of applications.
Software Development Kits provide the resources developers need to build applications for a specific device, operating system or web service.
SDKs usually include a development environment, a compiler and a debugger. Many SDKs contain sample code which you can use to identify best practices in working with a particular service.
SDKs are primarily used by companies to encourage developer adoption, so most SDKs you’ll use will be free and open-source.