API is an interface that allows software programs to interact with each other, whereas a SDK is a set of tools that can be used to develop software applications targeting a specific platform.
SDK? – A software development kit (SDK or “devkit”) is typically a set of software development tools that allows the creation of applications for a certain software package, software framework, hardware platform, computer system, video game console, operating system, or similar development platform.
What is a mobile SDK? – Short for software development kit, a programming package that enables a programmer to develop applications for a specific platform. Typically an SDKincludes one or more APIs, programming tools, and documentation
What is the use of Android SDK? – A software development kit that enables developers to create applications for theAndroid platform. The Android SDK includes sample projects with source code, development tools, an emulator, and required libraries to build Android applications.
What is the Java SDK? – The JDK forms an extended subset of a software development kit (SDK). It includes “tools for developing, debugging, and monitoring Java applications”. Oracle strongly suggests to now use the term JDK to refer to the Java SE Development Kit.