Before looking into the different types of measurements in detail, it's essential to differentiate between the other unit systems used by people depending on where they're in the world.
The Metric system is the most common unit system, which is widely used in lots of countries around the world. Popular metric units include metres, kilograms, litres, and more.
The Imperial system, also known as British Imperial, is another unit system prevalent in the United Kingdom. Foot, gallon, and stone are all Imperial units.

Standardization of measurement units

Measurements most commonly use the International System of Units (SI) to compare with other objects. The system defines seven fundamental units - kilogram, metre, candela, second, ampere, kelvin, and mole.

SI base units

ampere (symbol: A) – unit of electric current
kelvin (symbol: K) – unit of temperature
second (symbol: s) – unit of time
meter (symbol: m) – unit of length
kilogram (symbol: kg) – unit of mass
candela (symbol: cd) – unit of luminous intensity
mole (symbol: mol) – unit reflecting amount of a substance

Metric prefixes

Everyday use metric prefixes

Text	Symbol	Factor	Power
exa	E	1000000000000000000	10¹⁸
peta	P	1000000000000000	10¹⁵
tera	T	1000000000000	10¹²
giga	G	1000000000	10⁹
mega	M	1000000	10⁶
kilo	k	1000	10³
hecto	h	100	10²
deca	da	10	10¹
(none)	(none)	1	10⁰
deci	d	0.1	10^-1
centi	c	0.01	10^-2
milli	m	0.001	10^-3
micro	μ	0.000001	10^-6
nano	n	0.000000001	10^-9
pico	p	0.000000000001	10^-12
femto	f	0.000000000000001	10^-15
atto	a	0.000000000000000001	10^-18