What do you understand by unit conversion factors? How does it help to convert height in feet to height in meters?

Hint: We know that the conversion factor is a number used to change one set of units to a different, by multiplying or dividing. When a conversion is important, the acceptable factor to an equal value must be used.

Complete answer:
As we know that many various sorts of measurements that sometimes require conversions: length linear, area two dimensional and volume three dimensional are the foremost common, but you'll also use conversion factors to convert mass, speed, density, and force. Conversion factors are used for conversions within the imperial system feet, pounds, gallons within the International System of Units of Units SI, and therefore the modern type of the metric system: meters, kilograms, liters or across the two. A unit conversion expresses an equivalent property as a special unit of measurement. As an example, Sometimes, time is expressed in minutes or seconds instead of hours, while distances are measured in meters or cm instead of kilometers, or feet, or the other measure of length. A conversion factor is a numeric expression that permits feet to be changed to chains as an equal exchange. We know that one foot is $ 30.48 $ cm and one meter is $ 100 $ cm thus, relation between foot and meter is:
 $ 1\left( foot \right)=30.48\times \dfrac{1}{100}m. $
Therefore, $ 1\left( ft \right)=0.3048m $ .

Note:
Remember that the use of a unit depends on the situation, such as the area of a room is expressed in meters but the length of a pencil is expressed in centimeters and its thickness in millimeters. Thus, we need to convert one unit to another.