It depends on what variables are graphed.
Chat with our AI personalities
The line which has greater slope stands for the fast moving object
Only if you know your location (the coordinate on the distance scale and the time scale) where "you" are can you infer if the object is moving towards you (the absolute distance to the object is decreasing) or away from you (the distance is increasing).
Of course yes. An object is stationary when the graph is horizontal in a displacement-time graph.
The object is accelerating
It tells you that the speed of the object is not changing. The speed is represented by the slope in a distance vs. time graph, if slope doesn't change, speed doesn't.