Upper bound: A value that is great than or equal to every element of a set of data.

Lower bound: A value that is less than or equal to every element of a set of data.

Volume: The amount of 3-dimensional space something takes up 

Capacity: The amount that something can hold. Usually it means volume, such as millilitres (ml) or litres (l) in Metric, or pints or gallons in imperial.

Mass: A measure of how much matter is in an object. Mass is commonly measured by how much something weighs. Mass is usually measured in grams, kilograms and tonnes in Metric. 

Density: A measure of how much matter is in a certain volume. The density of water is about 1kg per litre.

Metric System: A system of measuring based on (i) the meter for length (ii) the kilogram for mass 

Imperial System: A system of weights and measured originally developed in England. For examples, (i) Length: inches, feet, yards (ii) Area: square feet, acres (iii) Weight: pounds, ounces