There are two basic types of photographic film: negative and slide. Negative film (the inverse of the actual image) is used to make positive color or black-and-white prints. Slide (reversal) film is generally only available in color and makes positive transparencies for projection.
Color negative film has the advantage of greater exposure latitude, which means you can over- or underexpose up to 3 stops and still get acceptable detail in prints, and it is available at higher speeds. With an exposure latitude of only 1 stop, slide film is far less forgiving but gives more faithful saturated color and higher contrast. It is generally slower so has less perceptible grain. Film grain or granularity is the random optical texture of photographic film and—depending on specific stock—becomes more noticeable as film speed is increased, especially in images with even or delicate tone.
Color films are color balanced for either daylight or tungsten light. Daylight film used in tungsten light produces images with a warm orange cast, while tungsten film used in daylight gives a blue cast. Conversion filters can be used to combat this, but ideally the correct film should be chosen to get true colors from the lighting. Black-and-white films work well with all common light sources.
There are many different brands and types of slide and negative film; each will result in different picture qualities and characteristics.