What's the difference between parenthesis $() and curly bracket ${} syntax in Makefile?

Question

Is there any differences in invoking variables with syntax ${var} and $(var)? For instance, in the way the variable will be expanded or anything?

Answer 1

The Basics of Variable References section from the GNU make documentation state no differences:

To substitute a variable's value, write a dollar sign followed by the name of the variable in parentheses or braces: either $(foo) or ${foo} is a valid reference to the variable foo.