When I open Terminal Window in Mac OS X, I can type bash and hit enter and I will see:

```
Last login: Fri Feb 20 14:30:56 on ttys000
Korays-MacBook-Pro:~ koraytugay$ bash
bash-3.2$ 

```

I can for example run commands such as **ls** or **ls -l** both in Terminal and in "bash-3.2$"

What is bash running under Terminal and what is Terminal itself?