Correlation vs. Parameterization

Parameterization is used when you want to take a value and turn it into a variable in order to make your script more realistic. For example, if you are filling out a form on a website, you may want to vary the value entered for a particular field.

Correlation is used when a recorded script includes a dynamic value (such as a session ID) and cannot replay. To resolve this, you make the dynamic value into a variable thereby enabling your script to replay successfully.