# Parameterization Parameters and variables are similar in that they are both stores of value, but they differ in purpose. Variables are usually utilized in functions _within_ the application as a way to pass a value. Parameters are usually utilized at runtime to pass values _to_ the application that determine its behavior in some way. Parameterization in load tests is a better practice than hard-coding values such as domains, which might change depending on the environment that needs to be tested. Parameterization is part of [[Making load testing scripts more realistic]]. [[Test parameters]] are a special type of parameter that specifically define the shape, intensity, and duration of load. [[Execution Parameters]] are parameters that are set at runtime and are passed to the script. ## Parameterization in [[Load Testing Tool]]s ### [[Parameterization in JMeter]] ### [[Parameterization in Gatling]]