Binary: Any system of two values. For example, on/off, 1/0, black/white.

Bit: Bit stands for binary digit. In computer science, a bit can be either zero or one. A bit is the basic unit of memory used by all computers. Bits can be stored as magnetic signals (hard drives), light signals (CDs, DVDs), and electrical signals (RAM, transistors).  

a) What is a bit and what does it stand for?

A bit is the same thing as a binary digit which is equal to 0-1. Bit is sort for binary digit. 

b) How many KB do you need to save the US constitution?

You need about ---------- bytes to save the US constitution.