An Introduction to Bits

A computer has — stored within it — millions or even billions of minuscule devices called transistors. These transistors detect the presence — or absence — of voltage and return a value of 0 — if it detects the absence of voltage — or 1 — if it detects the presence of voltage. These 0 and 1 values are known as a bit. The word: bit can be expanded to [b]inary dig[it]. Looking inside the brackets will yield the letters for the word: bit.

These transistors don’t detect whether there is absolutely 0 voltage going to it or any amount of voltage; but rather, these transistors detect levels of voltage and have a margin of error. For example, a transistor could receive .5 volts and that would still register as a 0; whereas a transistor could receive 2.2 volts and that would register as a 1.

Because a transistor can only output a 1 or a 0, it is necessarily the case that the voltage on a wire can represent only 2 things: presence or absence. What if we wanted to process more information? Well, we would need to use more wires. If we wanted to utilize, for example, 8 bits of varying information, then we would need to use 8 wires. Since each wire is carrying 2 possibilities: a 0 or a 1, and we are mixing and matching these pieces of information, we have 2^n possibilities, where n is the number of wires. An example might illustrate this better:

If you have 3 bits, you could have any of the following values:

0,0,0

0,0,1