A byte is a sequence of eight bases 2 numericals called "bits." We've already discussed this, so we're moving on. I just wanted to remind you of the terrifying and evil Part 6 that haunts you every night. So… One byte is 8 bits. One bit is the smallest possible measurement of any piece of data.
If you guessed that a kilobyte (KB) is 1000 bytes, you're absolutely right. One kilobyte is equivalent to 1000 bytes, or 10³ bytes. This is much easier to read for humans.
Someone might have told you at some point that a Kilobyte is 1024 bytes. Go ahead. Tell them that they're flat out wrong.
The "1024" concept comes from another unit of measurement called the Kibibyte (KiB). The International System of Units defines Kilo as 1000. Slap anyone who says that KB = 1024 B in the face for me, OK?