Not much of the universe was detailed in the movie so a lot of these changes were as the result of expanding on the universe and changing the way various systems worked, and the others are merely the result of transferring a movie into a suitable format for TV. Along with the obvious change of actors (there were a couple of exceptions, for example Alexis Cruz returned to reprise his role as Skaara), below is the full list of differences between the Stargate universe as established in the movie and the Stargate universe as established in the TV series:
Lots of name changes
- Sha'uri from the movie became Sha're in the TV show,
- O'Neil changed to O'Neill (and this is joked about throughout the series due to the stark contrast in personalities between the two characters),
- O'Neill's wife changed from Sarah to Sara,
- O'Neill's son from Tyler to Charlie,
- Louis Ferretti became Louis Feretti
- In the movie, the SGC is located in the fictional Creek Mountain, in the movie this becomes the real life Cheyenne Mountain complex,
- Abydos changes from being in another galaxy to being the closest planet in the network, in our own galaxy
- In the movie, Ra was the last of a dying race, which becomes one of many System Lords,
- Ra's servants are not Jaffa (no stomach pouches),
- The credits say that Ra's primary servants are named Anubis and Horus. Anubis later appeared as a half-ascended Goa'uld and Horus may have become Heru'ur, who had Horus guards.
The Stargate itself changed.
- In the movie it had a collection of 39 symbols unique to each gate, in the TV show each Stargate network has a collection of 38 symbols plus one unique symbol for each point of origin.
- The chevrons do not light up in the movie.
- It's not shown how they dial the gate on Abydos in the movie. In the show, they establish that there is a DHD that can do this.