Final answer:
In Physics, a base quantity is a physical quantity chosen by convention and practical considerations. A base unit is the standard for expressing the measurement of a base quantity within a system of units. Derived quantities, on the other hand, are physical quantities defined using algebraic combinations of base quantities.
Step-by-step explanation:
In Physics, a base quantity is a physical quantity chosen by convention and practical considerations, from which all other physical quantities can be expressed as algebraic combinations. A base unit is the standard for expressing the measurement of a base quantity within a particular system of units, defined by a specific procedure. On the other hand, a derived quantity in Physics is a physical quantity that is defined using algebraic combinations of base quantities. Derived units are units that can be calculated using algebraic combinations of the fundamental units. Each derived quantity and unit can be expressed in terms of the base quantities and units.