Cell Parts. Your body is made of about 10 trillion cells. The largest human cells are about the diameter of a human hair, but most human cells are smaller -- perhaps one-tenth of the diameter of a human hair.Run your fingers through your hair now and look at a single strand. bacteria is a single, self-contained, living cell. An Escherichia coli bacteria (or E. coli bacteria) is typical -- it is about one-hundredth the size of a human cell (maybe a micron long and one-tenth of a micron wide), so it is invisible without a microscope.
A cellular phone that uses the Global System for Mobile (GSM) network and can access multiple cellular phone service provider networks is called an unlocked GSM phone. A locked cell phone is sold by the cell phone service provider and cannot be used with any other provider.
It's important to understand that only some kinds of phones can be unlocked, namely phones that are compatible with the GSM (Global System for Mobile Communications) network. GSM phones contain a small, removable card, known as a SIM (Subscriber Identity Module), that is programmed with your subscription information and phonebook. A SIM card can be removed and placed in other GSM phones, allowing you to quickly and easily change handsets while retaining your contacts and carrier service.