Novice, does jdk include jre in java development?

JDK is a Java development toolkit. Simply put, JDK is a developer-oriented SDK, which provides the development environment and running environment of Java. SDK is a software development toolkit, which generally refers to software development packages, including function libraries, compilers, etc.

JRE, namely Java Runtime Enviroment, refers to the running environment of Java, which is aimed at users of Java programs, not developers.

If you install the JDK, you will find that your computer has two sets of jres, one in \jre and the other in the directory C: \ program files \ Java \ JRE1.5.0 _15. The latter set is less than the former set of server-side Java virtual machines, and only copies the server-side Java virtual machines directly. And when installing the JDK, you can choose whether to install this JRE located in the C:\Program Files\Java directory. If only JRE is installed without JDK, only one set of JRE will be installed in the C:\Program Files\Java directory.

JRE is like a PC. The Win32 application we wrote needs the operating system to help us run. Similarly, the Java programs we write need JRE to run. So after you install JDK, if you install two sets of JRE in two different places on the hard disk, you can imagine that your computer has two virtual Java PC, both of which have the function of running Java programs. So we can say that as long as your computer has JRE installed, you can run Java applications correctly.

Jre is like flash player, with which a computer can play flash, but you can't make flash animation.

Jdk is like Adobe's flash development tool. With it, you can make flash animation, which includes flash players, such as flash player.

Jdk contains jre, which is wider in scope and more in content.

So I installed JKD jre and installed it together.