Difference between Binary Coded Decimal (BCD) and Binary Number System

Binary Coded Decimal (BCD) Vs. Binary:

BCD		Binary
1	BCD is a coding system.	Binary is a number system.
2	Its base is 4.	Its base is 2.
3	It needs more bit to represent a number.	It needs fewer bits to represent a number.
4	It is easy to construct.	It is difficult to construct.
5	Example: BCD of 15 is 00010101.	Example: Binary of 15 is 1111.