What is the difference between “keyword” and “reserved word”?

Question

What\'s the difference between a keyword and a reserved word?

For example, in the proposal for concepts in C++ one can read the following statement

Answer 1

I guess keyword is a word used as "keyword" (like if, for, switch, etc...) while a reserved word is something you cannot use as variable name because it might become a keyword in a future version of the language.