To put it most simply, acrylic nails are are a mix of powder and liquid monomer that's combined into a blob of dough, shaped onto your nails with a brush, and then air-dried. "Acrylics do not require a lamp to cure, and they're great for changing the shape or extending your nails.
According to Apsara Nails, acrylics are ideal for people looking to change the shape of their nails, or want more length.