Glossary:
1, IDE ：
Abbreviation for Intelligent Development Environment. That is, the intelligent development environment. is a development tool. Common IDEs are adt-bundles and Android studio. Both require jdk to be configured.
2,ADT：
Abbreviation for Android Development tools. Namely Android development tools. ADT is a plug-in for Eclipse. It acts as a bridge between Eclipse and the SDK.
3,SDK：
Short for Soft Development Kit. Software Development Kit. In Android, it provides developers with library files and other development tools.
4,JDK：
Java development kit. Including the Java runtime environment, Java tools and Java basic class library.
5,NDK：
Concepts:
(1).NDK is a collection of tools. Help developers to quickly develop C/C++ dynamic libraries.
And can automatically package so and Java applications together into apk. The help of these tools to developers is enormous.
(2). NDK will be the beginning of Android platform development to support C development.
Function:
(1). Code protection. Since the Java layer code is easy to be decompiled, it is very difficult to decompile the C/C++ library.
(2). Existing open source libraries can be easily used. Most of the existing open source libraries are written in C/C++ code.
(3). Improve the execution efficiency of the program. High-performance application logic will be developed using C, thereby improving the execution efficiency of the application.
(4). Easy to transplant. Libraries written in C/C++ can be easily reused on other embedded platforms.
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Well, I admit it's just to explain the NDK and everything else is an add-on. . .