CCENT (ICND1)Networking 101

What is Binary?

Bit’s, crumbs, nibbles, bytes, megabytes ???

Ever wondered why when you buy a 250 Gigabyte hard drive and you format it, you never actually get 250 Gigabytes??? Well it’s all in the exact wording used, and how the information is reported to you.

If we understand the terms of binary, and the difference between a Megabyte and a Megabit, the answer becomes clear.
Firstly, Binary is based on a 2-base number system. The ‘2 numbers’ are 0 and 1 (otherwise known as the “Off” and “On” bits).

A bit, is purely a representation of one value, either a ‘0’ or a ‘1’
A crumb, which is not commonly known or referred to, is a representation of 2 bits (00, 01, 10 ,11)
A nibble, also not that commonly known, is 4 bits, or half a byte. (0000, 0001, 0010, 0011, 0100, 0101, 0110, 0111 etc)
A byte, is a collection of 8 bits, and hence there are 8 bits in a byte. (00000000, 00000001, 00000010, 00000011 etc)

bit bit 0 or 1
byte B 8 bits
kibibit Kibit 1024 bits
kilobit kbit 1000 bits
kibibyte (binary) KiB 1024 bytes
kilobyte (decimal) kB 1000 bytes
megabit Mbit 1000 kilobits
mebibyte (binary) MiB 1024 kibibytes
megabyte (decimal) MB 1000 kilobytes
gigabit Gbit 1000 megabits
gibibyte (binary) GiB 1024 mebibytes
gigabyte (decimal) GB 1000 megabytes
terabit Tbit 1000 gigabits
tebibyte (binary) TiB 1024 gibibytes
terabyte (decimal) TB 1000 gigabytes
petabit Pbit 1000 terabits
pebibyte (binary) PiB 1024 tebibytes
petabyte (decimal) PB 1000 terabytes
exabit Ebit 1000 petabits
exbibyte (binary) EiB 1024 pebibytes
exabyte (decimal) EB 1000 petabytes


So based on the above, I have a hard drive that has ‘250GB’ written on the casing. If  I right-click on my drive in windows, and go to properties, I see that drive size as 250,056,704,000 bytes (250GB), which is 232 GiB.

One thought on “What is Binary?

  1. I started CCNA on Monday and I somehow saw you browsing your website while explaining something.I don’t regret coming here,it’s been very educational. I’m busy learning binary like crazy. Thanks a lot.

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