Variable is by definition mutable.
Constant is by definition immutable.
Why can't people get it through their heads in 2025? (I'm looking at you, Rust)
replies(4):
A true constant won't change between runs of the code. I.e. it is essentially a symbolic name for a literal.
A constant variable OTOH, varies in different executions of the code. So, its invariance is linked to an execution context.