I understand the term "Parameter expansion" (A.K.A "Variable expansion") to be an umbrella term for several unrelated operations in shell-scripting in general and in Bash in particular, such as:
- Variable substitution.
- Line splitting in case of 2 or more values in the same line.
- Globbing a variable of a particular scope.
and maybe more.
If I understand the philosophy behind this term correctly, we "expand" the variable from being just a variable, to be a more influencing stream of data (say, a substituted value) - it's now expanded to be a variable that something was done with.
Is my understanding of term accurate enough in general and are there any more operations under this umbrella term that should be mentioned in an answer?