A reporter is a type of journalist. He researches and presents information.
The gathering of information is part of his job and called "reporting" as distinct from the production part (writing). Their reports can be either spoken or written. He works for different sorts of mass media (newspaper, TV, radio etc.)
Journalist in common language usage is a person who works for a newspaper. Their reports are written.
"Journalist" can include reporters, editors, columnists etc.