Definition

Primary active transport is the transport of molecules against a concentration gradient through the use of energy generated by ATP

Secondary active transport is the transport of two distinct molecules across a membrane using energy in other forms than ATP 

Number of molecules transported

A single molecule is transported

Two types of molecules are transported simultaneously

Energy source

Uses energy generated from ATP

The concentration gradient of driving ion supplies energy for the transport of the driving ion/molecule against its concentration gradient  

Number of substances transported

May transport one or more substances

Must transport more than one substance

Types of transmembrane proteins used

Transmembrane proteins are specific to the ion transported through them 

Both antiporters and symporters are used in secondary active transport

Types of molecules transported

Ions like sodium, potassium, and calcium are transported across cell membrane

Ions like sodium act as the driving molecules 

Examples

Sodium potassium pump, calcium pump in muscles 

Glucose-sodium pump, sodium-potassium pump