What do the terms patent pending and patent applied for mean?
They essentially mean the same thing, which means you’re asking the patent office to finalize your request to issue a patent which they may or may not do, but during the time they’re answering that question, so to speak, you get to say “Patent applied for,” or “Patent pending.” You don’t have any right to stop people from making, using, or selling your invention, unless and until the patent issues, but you get to say patent pending and your competitors don’t know when you filed, whether it’s been a year or a minute. They don’t know … they can’t judge really very accurately whether your patent might issue tomorrow or five years from now. It does have a chilling effect perhaps on the competition.