From Netflix:

High above a war-torn future Earth, Cmdr. Jack Harper is maintaining the planet’s defensive drones when a crippled starship enters his territory. Its sole occupant, a mysterious woman, leads Harper to shocking truths about humankind’s legacy.

Good digital graphics, plausible plot and the usual really bad guy (a machine named TET) versus some nice survivors make this nothing-special sci-fi film bearable. Fortunately Tom Cruise does not try to act, pulling instead that old trick of keeping a perfectly straight face and letting you supply appropriate emotions on his behalf.

If the ending confuses you, you might try believing the plot description in Wikepedia.

If you have nothing better to do, then the adventure may not be a total loss.