I have a bit of confusion about making saves due to some battle reports I have seen. When rolling to make a save, is it based on wounds given, the number of shots given, or does it change depending on what it is Some examples'

Example 1 - I fire my Dark Lance at a vehicle and it hits and wounds causing D6 Damage. Do they roll based on the one hit, and then I make a the roll for wounds, or do they have to wait until I roll the D6 for damage, and roll based on how many woulds they receive.

Example 2 - I fire my Disintegrator Cannon hitting once causing 2 wounds automatically. Is my opponent making one save for one hit, or 2 saves for wounds?

Thanks for the help!