Stage lighting and visual effects for bands have come a long way from the days of photo-reflectors clipped to a mic stand and flood lamps with colored cellophane taped in front of the bulb. There's a huge range of high-quality, affordable lighting effects and controllers available today. In fact the sheer number of them can be a little overwhelming for first-time buyers, and even for more experienced users when new technologies like LED fixtures enter the picture. Add the complications of whether you're buying lighting for band performances of DJ shows, and let's see if we can perhaps simplify things for you just a little.
There are three types of lights you'll need: wash, spot, and effects. Wash lights, as you might guess from the name, bathe the stage in light, whether white or colored. Most lighting designers will divide the stage into sections and then provide a separate wash for each section. This way, you can have a variety of colors on stage, giving each performer their own space. Generally, you'll just par cans for this, either multiple incandescent with different colored gels, or, for a more compact system, newer LED par cans with RGB LEDs that can do multiple colors with a single fixture. You may also want fill lights on the sides to create some shadows and contrast, or the stage may look flat.