Computers use the base-two system, as it is easier to implement with electrical current.

It is called the binary system ...and basically operates on an 'off' and 'on' basis.

The word 'bit' is an abbreviation for 'B'-inary dig-'it'.

Zero equals 0.

One equals 1.

Two equals 10.

Three equals 11.

Four equals 100.

Five equals 101.

Six equals 110.

Seven equals 111.

Eight equals 1000.

Bits are bundled into 8-digit collections called bytes.

And with an appetite like mine, you need megabytes.