Q:

What is json.js and json2.js for?

I'm in the process of learning backbone and I keep seeing these libraries mentioned.
Can't one just use two simple functions on the client, 
JSON.stringify and JSON.parse
for JSON functionality?
Particularly, this tutorial here.

A:

Some older browsers don't have these JSON functions built in - so the JSON JavaScript library contains code that poly-fills these older browsers to work just like the newer ones.
The notable exceptions are IE 7 and below.

