You have a bunch of options. This is like the Vaping Renaissance we're going through.
1. A cartomizer. It's a tube filled with polyfill that you soak and vape. I recommend low resistance (LR) on an ego or kgo.
2. A clearomizer. Like a cartomizer, but clear.
3. A wicked tank, like the Vision Vivis, Stone, etc. it's a tank with wicks hanging down that you can fill and vape.
4. A dripping atomizer - just a simple burner you drip on here and there for instavapor.
5. An atomizer/cartridge system (CE2). Uses an atomizer and a cartridge full of juice, usually with a cone over it to stay pretty
6. A dual coil cartomizer. These are made by smoktech and can range from slightly big to flipping huge.
7. A tank. This is a system with a cartomizer with a hole punched or slotted into it that is then inserted into a tank made of plastic, glass, or metal. The tank refills the cartomizer as needed for longer vaping.
There's more out there, like variable voltage, variable wattage, and bottom feeding, but this should get you started.