There are actually two different kinds of tapes that are commonly referred to as plumber’s tape. One type of tape should be more appropriately called Teflon tape. The other type of plumber’s tape, on the other hand, should be called metal strapping instead. In either case, each type of tape is more commonly called plumber’s tape because plumbers are the professionals who most commonly use them.
The first type of plumber’s tape – Teflon tape – is used in sealing the pipe threads from any leaks. Teflon tape is a very thin, white tape that is wound around the thread of the pipes in order to fill in the gaps between the threads. The tape, which has a silky texture, also serves as a lubricant for the pipe threads when the fittings are tightened. Teflon tape is not an adhesive tape and will not work if you use it for sticking things together.
The other kind of plumber’s tape is not really a tape but a kind of strapping. This is a flexible strip made of metal that is possesses holes placed regularly all throughout the length of the strapping. This “plumber’s tape” is usually used in giving additional mechanical support for pipes. But, interestingly, people have been able to find different creative uses for the metal strapping.
Both the teflon tape and the metal strapping can be readily purchased from any hardware store or plumbing supply store. When buying plumber's tape, make sure that you know specifically what kind of tape is needed. But this is an easy thing to do because both "tapes" are so different from each other.