What are fundamental quantities?

Fundamental quantities are the "building blocks" of measurement. Just like you need flour, sugar, and yeast to make bread, you need these basic quantities to describe almost anything in physics.

There are generally considered to be seven fundamental quantities, but in secondary school physics, we focus mainly on three to start: Length (measured in meters), Mass (measured in kilograms), and Time (measured in seconds).

Every other quantity, like speed or force, is made by combining these three. For example, Speed is Length divided by Time. We call those "Derived Quantities".