Perharps you should look into some websites or books that teaches you these. Here are some basic information.
1. There are Black and White (B&W), colour, infrared films as seen in the market.
2. Slides are just like those pictures you put in an old projector for slides. We call it Positive as you do not need to print it to see it, just put it under a light source (say under a room lighting) and you can see the slides.
3. Negative are films, which the dark area of a picture becomes white and bright area becomes dark. But I still do not know the technical area why it is orange in colour. You have to develop it to see the real picture.
4. Any SLR camera should be able to use any B&W, colour slide and negative.
There are too many pros and cons to list here for both types, but in general when you take a picture a bit too dark in slide, it will be harder for you to correct it (make it brighter hence the correct brightness you want) than compared to negative. Also, there are more choices in negative than slide. Slides are generally more expensive than negatives as less people use them. But as you can view them directly without printing them on paper (under a light source or what we call a light box), it is often cheaper than negative in overall cost.
2. Slides are just like those pictures you put in an old projector for slides. We call it Positive as you do not need to develop it to see it, just put it under a light source (say under a room lighting) and you can see the slides.