BSD, Bash and Shells?

When I use Mac OS X's Terminal the UI is some what easier than that of Linux...

I this just a shell or something because using Bash is a pain in RH's Linux 9. It's so sensitive about case etc. ???

In that way what is the shell that OS X uses as it's default

Bash is on OS X (OK Duh) and they reffer to BSD as a subsystem so isn't just some sort of API that can be incorpt.ed into Linux?

to find out what shell you are using, try entering this at the command line (it should work):
echo $SHELL

OS X uses tcsh by default.

Any UNIX (or variant) OS will be highly sensitive about case. A will always be different to a.