EPC and RFID
EPC (Electronic Product Code) is simply a number, typically from 64 to 256 bits long, that is being standardized so thousands of trillions of items in the world can be assigned a unique identification number, a unique EPC, which is the equivalent of an electronic bar code. This is vital so that everyone uses one type of system and not their own code - which would lead to great confusion because so many different people need to read the same tag. "Closed" systems - such as a library, use their own numbering system (i.e. not EPC) as books may only be read in that library and not all around the world. That is why we see many case studies of tags being used in small "closed" applications - they don't have to wait for standards, but tagging things on a large open infrastructure means there has to be just one way of identifying everything, in this case EPC. This requires standardization which in turn needs time for everyone to agree on the right way to structure the numbers - which was one purpose of the Auto-ID Center. Now this project is managed by the newly formed EPCglobal which will licence usage in a similar way to barcodes. The same organisations are involved with both - UCC and EAN. In the simplest terms, EPC is just a number.
RFID is the favoured medium used to transmit and read that number remotely, e.g. through packaging, or many tags at once for example. RFID systems don't have to use EPC, as in the library case and many others, but if they do the readers need to use the same type of database to determine what the EPC number is and which item it is connected to. This database is known as SAVANT.
Auto ID Center developed and researched the EPC and SAVANT and a few other software add-ons. It allowed all the sponsor members to agree on how the code should be structured. Companies joined the Center to have a say in how the items should be numbered. Now EPCglobal is standardizing it so people can use it like they do barcodes - companies pay UCC and EAN, the standardization organisations, to use a range of EPC numbers. The more EPC numbers you need (the more items you tag), the more you pay - this is similar to how barcodes are cost structured. The Auto-ID Center decided that RFID would be the medium to read EPC tags, but they did not determine the type of RFID system to be used - so people can use different frequencies, for example 13.56MHz and UHF, to read the same code.
Therefore EPC and RFID are complementary, but EPC is not the only way to do things. For example, RFID is really big in transport for contactless smart cards, and these were standardized a long time ago and use a numbering system that is completely different to EPC.