If you are not sure which type of paint you require, please see here the main differences:
Basecoat – Clear over Base. Basecoat is the paint, which requires a Clear Coat (Lacquer) to be applied after, to provide Gloss and Protection. Most popular and most likely if you car is a metallic.
2K Acrylic – 2K Acrylic provides gloss direct from the gun and therefore does not require Clear Coat after. However this paint requires an activator/hardener for the paint to dry. Solid colours (not containing particles such as metallics) are available in 2K Acrylic, rarely can you get metallic and mica colours in 2K Acrylic.
Cellulose – For Classic Cars, Cellulose does not require a lacquer for gloss, or an activator for it to dry. It will need flat and polishing to bring a gloss effect.
Waterbase – Most modern cars are painted and refinished in Waterbase, a compliant Basecoat that contains water as well as solvents.