Star Wars: X-Wing is the first flight sim game set in the Star Wars universe created by LucasArts. It was released in 1993 for PC MS-DOS only and it was followed one year later by Star Wars: TIE Fighter.
Star Wars: Tie Fighter is a space flight and space combat simulator game released in 1994. It's the sequel to Star Wars X-Wing. It was designed by Totally games, and released by LucasArts.