Like camera photography, you generally need a good source of light to capture quality video images. This may come from natural light, artificial light or flash. If your camcorder has low light recording capabilities that will help.
When shooting videos you need a light that comes on and stays on as you need adequate light for night filming. A good lighting system should be able to reduce redeye and turn itself off if you forget.
Most camcorders enable you to attach a lighting system to them. Some lighting equipment comes with filters, reflectors, AC/DC adaptors, cigarette plug adaptors, batteries and chargers and barndoors while others are just the basic system and battery. Some don't even include a lamp. Some models operate on the camera's power source so you don't need any extra cables or batteries.
A good system will allow you to tilt the light and easily change the lamp. You can also buy more complex off camera lighting systems for your video needs. Lighting systems come in various sizes, shapes and styles. On camera lighting can range in price from about $25 to $400. You can buy the lighting items separately or in kits.