Unlimited - you can buy a Genesis light by itself, which includes the studio flash, a modeling lamp, power cord, sync-cord that connects to your camera (so when you press the button the flash fires too), and a reflector dish that bounces all your flash light forward when fired. The modeling lamp does stay on continuously, but is much dimmer than a flash tube of course. Modeling lamps are bright enough to aim your lights and see exactly where they're going to hit the subject and how it'll look when the flash goes off. Many of today's studio lights use "proportional" modeling lamps, meaning if you turn the power of the flash down to 1/2 ... the modelling lamp dims to 1/2 as well. 3/4 power equals 3/4 power modeling lamp. etc. Incredibly useful for setting up the shoot when you want one at full power as your main light, and another at a lower power to just fill in the shadows or create some dynamic lighting.
So that's the Genesis 200 by itself. They also sell a Genesis 200 - one light KIT. The kit includes all the above -AND- a 10' stand with brass mounting head to screw your light onto ... and a 45" umbrella that can have the flash bounced off it -OR- shot through its white diffusion material. Super versatile, but costs more.
Finally - you can buy a two-light Genesis 200 kit. That's 2 lights, 2 stands, 2 umbrellas, etc. What's kinda silly is their light by itself was the exact same price as the one-light kit so no reason to not purchase the whole kit for its addt'l goodies. Not sure it's still priced the same, but was when they were introduced earlier this year.
Genesis also has a 400w/s light kit in the same 3 versions. Double the power and light output ... but a lot more money. It's also avaiable as just the light and cords ... a single light kit with stand/umbrella ... or the two light kit with all the goodies.