What are the stylistics of a typical Southpaw?

[Jimanuel Boogustus]

I often hear and read about the dreaded Southpaws...

Apparently, Lefty's should be drowned at birth

But seriously. I'm very much into looking at how styles make fights and how the smallest of manoeuvre or habit of repetition can give any particular fighter the advantage over another evenly matched opponent.

With southpaws however, I'm left feeling like I'm missing something.
I don't box. Never have, never will. So unfortunately i can never gain 1st hand experience of this apparent conundrum.

Appart from the obvious lack of familiarity that comes with facing a southpaw. I could never figure out WHY certain things were given as fact for example:

• an Orthdox Rear Hand is a key pucnh against a Southpaw

Why is this

But more than that... Really what is a Southpaw all about?
What works for them and what works against them?