A bit is a single number: 0 or 1. If you combine several bits together you can write larger numbers, like 00, 01, 10, and 11 are ways to write 0, 1, 2, and 3 respectively.
A digital image is really just a series of numbers: a number for how red the upper-left part should be, a number for how green the upper-left part should be, a number for how blue the upper-left part should be, then similar triples for each other part of the image. An 8-bit image uses 8-bit numbers, which range from 0 to 127, for each of those. A 16-bit image uses 16-bit numbers.
Computers (gaming systems) store everything as numbers, not just images. A 16-bit system is designed to work with 16-bit numbers easily, and needs to work harder to accommodate larger numbers and wastes space when dealing with smaller numbers.
Edit to add an actual 5 year old analogy:
Suppose that you are practicing writing and adding numbers at school. Your teacher gives you strips of paper with four blanks each to write numbers on. This is a 4-bit system. If you want to write down numbers like 3047 and 1382, this system is perfect. If you want to write down numbers like 12, 73, 42, and 18 you can do that too. You could even save space by writing two of these shorter numbers on the same strip, but then you need to remember that 1273 is the number 12 and the number 73, not the number 1273. If you want to write down numbers like 17345 you have to tape two strips of paper together.
Latest Answers