A copy is a reproduction of something — it looks identical to the original. You might ask your sister to make a copy of your nephew's adorable painting so you can hang it on your fridge.
You can use the word copy in several different ways. Your doctor's office may keep a copy of your insurance card on file, and they may copy it again every year. This verb form of copy means "to replicate or reproduce." You can also copy down what your teacher says in class — in this case, you're not making an identical copy, but writing the basic ideas. The Medieval Latin root, copia, "reproduction or transcript," comes from the Latin word copia, "plenty."