So the big question is that what is binary code and why do computers use it? Well it is a coding system using the binary digits 0 and 1 to represent a letter, digit, or other character in a computer or other electronic device and computers use it as their language to understand instructions given by the user.

As you can see that this is a 4-bit table so how do you convert into denary (the numbers we use to count). Well it is simple, for example if I have the binary code 1101 than to convert you arrange the numbers in the table. The first 1 goes under 8, the second 1 goes under 4, the 0 goes under 2 and the 1 in 1. So if you add up 8+4+1=13 so 1101 is 13 in denary. The same rule also applys to the 8-bit table below.