SDK: the toolkit for building apps
An SDK (software development kit) is a set of tools for developers: libraries, compilers, emulators, documentation and code samples for building software for a specific platform (Android, iOS, Windows, game engines, services).
In plain words
An SDK is like a LEGO set with instructions for a particular model: ready-made pieces (libraries), tools (compiler, debugger) and diagrams (documentation). You could build something without the set, but you would have to make every brick yourself.
How it works
- The developer installs the SDK and a development environment.
- They write code using ready-made libraries and the platform's APIs.
- They build the app with the SDK's tools.
- They test it on an emulator or a real device.
- They publish it to an app store.
Where you'll see it
The Android SDK (with Android Studio), the iOS SDK (with Xcode), SDKs for game engines (Unity, Unreal), service SDKs (payments, maps, AI models) and SDKs for drones and robots.
Does it matter when buying
If you want to make apps or games, SDKs and development environments are free to start with. Begin with the official Android courses or Swift Playgrounds, or Unity for games. For ordinary users, the SDK is invisible.
Myths
- Myth: An SDK is a programming language. Reality: It is a toolkit; the language (Kotlin, Swift) is separate.
- Myth: Developing apps is very expensive. Reality: The tools are free; only publishing in some stores costs money.
FAQ
What is an API?
A set of rules for how programs access a system's or service's functions; often part of an SDK.
Which language should I learn for Android?
Kotlin.
And for iPhone?
Swift.