Oh, Those Terrible Units

There are some numbers and units. Numbers are numbers. Units are units. Numbers informs how many. Units inform about two things:

how many
of what.

The SI Base Units

Name	Unit symbol	Quantity
metre	m	length
kilogram	kg	mass
second	s	time
ampere	A	electric current
kelvin	K	thermodynamic temperature
candela	cd	luminous intensity
mole	mol	amount of substance

IT Base Units

Name	Unit symbol	Quantity
bit	b	number of bits
byte	B	number of bytes
bits per second	bps	number of bits per second

Have you seen the difference? BYTES and BITS?

Word Of Truth

1 BYTE = 8 BITS
1 B = 8 b
bit represents logical value (True or False), (0 or 1)
there is nothing smaller than 1b
you cannot have half of a bit – what is the half of False?

SI Prefixes

Standard prefixes for the SI units of measure
Multiples	Name	kilo-	mega-	giga-	tera-	peta-	exa-	zetta-	yotta-
	Symbol	k	M	G	T	P	E	Z	Y
	Factor	10³	10⁶	10⁹	10¹²	10¹⁵	10¹⁸	10²¹	10²⁴

These symbols are used for avoiding too many zeros. So instead of 1000m you can write 1km and instead of 1000000B you can write 1GB. This is another problem. Normally 1 kilobyte = 1024 bytes, yea, the IT world is wierd. For distinguishing between 10³ = 1000 and 2¹⁰ = 1024 someone created some binary system:

Binary prefixes
Multiples	Name	kibi-	mebi-	gibi-	tebi-	pebi-	exbi-	zebi-	yobi-
	Symbol	K	Mi	Gi	Ti	Pi	Ei	Zi	Yi
	Factor	1024¹	1024²	1024³	1024⁴	1024⁵	1024⁶	1024⁷	1024⁸

Now we’ve got 1024B = 1KiB and so on.

The Problem

Why am I writing all that? Because I don’t understand why many people in the IT world, including many programmers, still don’t know that this is important to write according to some standards. This is like a language: you have to use correct grammar so others have the chance to understand correctly what you say.

Some Examples From Web

1KB – this means 1 Kelvin Byte – I have no idea what it means. Author could think about: 1kB = 1000B or 1KiB = 1024B.
1mb – funny… 1 milibit, this is 0.001 of bit. Bit is a logical value, means True or False, 0 or 1. How can you have 0.001 of True or False? Maybe someone wants to write 1MB = 1,000,000B?
1mB – another funny, not found so often. This means 1 milibyte = 0.001 B. But 1 byte is 8 bits. So this is 0.008 of True or False.
1gb – sorry, I have no idea what the ‘g’ is.
1gB – the same as above.
1kb – often author wants to write 1kB because 1kb = 125B - quite unusual number of bytes.

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