Intro to Binary,Decimal and Hexadecimal

A binary or base-2 is a number that only contains 1 and 0. As we all know, "bi" means two. In the word binary, it derives its name from the fact that the digits in a "Binary" number can only have two possible values, 0 or 1. It is also called "base-2" based on the fact that the column values are the powers of 2.  (i.e. 2^0  2^1  2^2  2^3  2^4  2^5  etc. )  
Some of these examples are: 0, 1, 10, 01, 1010, 00001111,etc. 

A decimal or base-10 is simply the numbers that we see. Decimal numbers consist of the digits from 0 (zero) through 9. The following are examples of decimal numbers  
 3  , 76 , 15 , 32423234 , 890 , 53.

A hexadecimal or base-16 is basically a mixture of numbers and letters. For example, ABC, 3DF, 12E, etc.