When I install the Oracle Java JDK, it also installs separately a JRE. Like so:

JDK:

```
C:\Program Files\Java\jdk1.7.0_40

```

JRE: 

```
C:\Program Files\Java\jre7

```

Isn't the JRE a subset of the JDK? Why would I need the JRE executables and libs twice?

In particular, is there a difference between the `java.exe` in the `JRE/bin` and the one in the `JDK/bin`?

I believe adding JDK/bin to the path should suffice.

I'm on Win 7 (in case that's relevant).