I think dreams have meaning. Sometimes that meaning is just your subconscious mind's way of working through issues while you sleep. For instance, I watched a video on this site of a dog being rescued from a python and then that night I had a nightmare about my dog being injured. It was just my mind's way of dealing with the fear that something bad would happen to my dog that was triggered by that video. I don't think it was prophetic -- just more like some kind of psychological clean up or something.
But other dreams I've had have been different. I'm still not sure of the purpose of some of them, but they seemed like genuine messages that I was supposed to pay attention to. Now, whether that message is just my subconscious trying to send me information or some outside force trying to pass on info to me, who knows? Logically, I assume it is the former, but some dreams definitely feel like the latter. For instance, I had a dream that I broke a particular glass that I owned while washing the dishes. At that moment, voices started telling me, "Pay attention. This is important. When you see this, it is about to begin." I couldn't see anyone and the voices appeared to be coming from above me. I kept saying, "What does this mean? What will begin?" But they just kept repeating the message while I was getting more frantic to find out what they meant. Then I woke up. I was totally shaken by it because it felt so real. In fact, it freaked me out so much that I threw away that glass. I was afraid I would break it while washing it and have a meltdown. So, if it was an actual message from angels or the universe or something, well, I pretty much refused to listen to it. But, no consequences from that refusal yet -- so that probably means it was nothing more than a weird dream that was very vivid.
My husband, though, sometimes has dreams about his late father. Those do seem to have relevance. In one, his father told him that our first child was going to be a girl. I was pregnant at the time and was certain we were having a boy. But, nope, we were having a girl. He said it seemed so real to him -- so I'm more open to thinking that those dreams are just a way for his father to communicate with him from time to time. Maybe that is just wishful thinking, though.