What are binary numbers, and how can you convert from binary to decimal and back again?

Binary numbers are a bunch of 1's and 0's, you can use binary to get normal numbers. If the binary number is 00111, you read it from right to left and you only count them if there is a 1 in the binary code. From right to left the numbers would be 1, 2, 4, 8, 16, 32, 64, 128, and so on. Once you have all the numbers with the 1 next to them you add them up and get the final number