From Bash Reference Manual, a parameter:
A parameter is an entity that stores values.
It can be a name, a number, or one of the special characters listed below.
A variable is a parameter denoted by a name.
Is a variable is a parameter A, denoted by a parameter B which is also a name? How do you understand the concept of a variable?
since a parameter stores values, does that mean a parameter is a block in memory?
I never heard of the concept of "parameter" in other languages such as C, C++, Python. Do the distinct concepts of parameter and of variable exist in programming languages besides bash? What are their definitions in programming languages?