Final answer:
The definitions of convert in the question have in common the concept of changing units of measurement using conversion factors.
Step-by-step explanation:
Unit conversions involve changing a value expressed in one type of unit to another type of unit. This is done by using conversion factors, which are ratios relating equal quantities of different units.
Conversion factors are used to convert one unit of measurement into another. Dimensional analysis (unit conversions) involves the use of conversion factors that will cancel units you don't want and produce units you do want.
The important thing to note is that all the definitions of convert in the question have in common the concept of changing from one unit of measurement to another, using conversion factors.