Answer 1

keyword is a word that reserved in program languages and used in statements. They are using to perform common tasks.
it's important that you can't name your variable like keyword (like you can't declare 2 variables with same name).
examples of keywords (almost all of them are same in different program languages):
1) data types.
2) if-else (using to checking is conditional true or false).
3) loops: for, while, do-while.
4) const (using to declare a constant).
5) try-except (using to handle exceptions).
and many others.