Most Helpful Girl
I had them.
I got a full acrylic set and they put them on when my nails were short. Basically they glue the tips on, then put acrylic over your entire nail from bottom to tip. The acrylic is either a paste that hardens when it dries, or a powder mixed with a liquid that hardens and dries when they come together. I've seen both kinds. Then after it dries they file it down and often drill it with an electric nail file (this can be damaging to nails if done too extensively) Then after they file/(drill) it and shape the tip, they paint it with polish and dry.
They can look nice if you don't keep them too long. After a while if you keep getting them filled every few weeks (where they trim them, reapply the acrylic and repaint), your natural nail underneath will get long and over a few months it will grow enough that the tip will eventually be trimmed off and only your natural nail will be coated.
However, after you take the acrylic off your nails will be thin and brittle and break easily. But, it is not permanently damaging because the new nail growth will grow in normal again if you don't acrylic it.
I liked having it because my polish stayed on well.