A "prefix" is a term that often appears just before a property's value in text.

Example Sentence: "The material showed a current density of 550 mA cm−2."

For the property "Current Density", useful prefixes to define would be:

• density of current
• current density of
• current density is
• current density increased to

A "unit" is the measurement standard that follows a numerical value.

Example Sentence: "The material showed a current density of 550 mA cm−2."

For the property "Current Density", useful units to define would be:

• mA cm-2
• A/cm^2
• A cm-2