Binary subtraction is a method of subtracting numbers in the binary numeral system, which uses only two digits: 0 and 1. Similar to decimal subtraction, it involves borrowing when the top digit is smaller than the bottom digit. For example, subtracting 1 from 0 requires borrowing from the next left digit. To perform binary subtraction, you align the numbers and subtract each column from right to left. If you need to borrow, you convert the next left digit into a binary 1, which represents 2 in decimal, and adjust the current column accordingly. This process continues until all columns are processed.