What do machines represent in the motion picture, The Terminator?

Throughout the film, shots of even the most normal of machines remind viewers of the fate of the future. When we first see the Terminator appear, he shows up directly next to a large bulldozer. This bulldozer reminds us of the previous scene from the future, in which bulldozers chase down humans survivors hiding in the rubble of Los Angeles. Wherever machines pop up, the dire, dark future ruled by machines returns to the mind of the viewer.