Fundamental physics terms

Scalar

Any quantity that measures only magnitude

Vector

Any quantity that shows both magnitude and direction

Unit

The label used for a measurable quantity

Base unit

A unit without prefixes

Derived unit

Combination of fundamental units that result in a new unit of measurable quantity

SI unit

International system of units

Two systems of units

Metric and English(Imperial)

Primary unit

MKS

Definition of physics

The branch of science that studies matter, energy, forces, motion, space, time, and their interactions.

What system is primarily used in physics

MKS