Acrylic nails are applied using a monomer (the 'liquid'), and a polymer (the 'powder'). The two ingredients are combined and the resulting bead of soft acrylic is placed into your nails and shaped into an artificial nail enhancement. Acrylic hardens by exposure to room temperature air in about 2 minutes for most brands. Acrylic is the most common form of nail enhancement offered in salons. If the tech uses cheap acrylic products, then the result is usually shoddy looking nails that yellow very easily, and look very fake. It's always best to use top of the line nail products when doing either acrylic, or gel nails on someone. The end result is usually so much better looking, and longer lasting than with cheap products.
UV gel nails are made from chemicals which are part of the acrylic family, but are different in a few ways. The most noticeable difference is that the nail gels themselves are in fact not powder - as many people believe it is, but instead it is? You guessed it, UV nail gels are a gel! They look exactly as the name implies, like a 'gel.'
The gels are applied to your nails in several thinly applied layers, and each and every layer MUST be cured under a UV lamp for about 2 minutes each. This is quite different from the way acrylic nails harden - by exposure to air. Gel doesn't cure by exposing it to air. It uses the UV light emitted from the UV lamp to start the process of polymerization, and cure into the finished product. This takes place in 2 minutes - normally. Some brands need to cure for 3 minutes. To sum it up, UV gel nails are non-yellowing, non-toxic, and quite durable as well. They are also much more realistic looking than acrylic nails are, and you can go a bit longer between fills.