The decimal system is perhaps, the best known of the number systems. It got its name because it is a base-ten system. The value of each place is ten times greater than the value of the place just to its right. A thousand is 10 times 100; a hundred is 10 times 10; ten is 10 times 1.
For example, the value of 2,345 is:
ie. 2x1000 + 3x100 + 4x10 + 5x1 = 2,345
On the other hand, the computer uses the binary numbering system. Here, the value of each place is two times greater than the value of the place just to its right. Binary means two thus the system is represented by 0s and 1s.