Radio Frequency Identification (RFID) is a technology that allows the identification of tagged items without a line of sight. It includes a tag, a reader and a computer system. A tag containing a tiny microchip and an antenna is placed on an object. Most of the tags, which usually carry information in the form of a unique serial number, require no external power. These tags are known as "passive" tags. When devices called readers are placed close to tagged objects, a low power signal is sent out to the tag. The tag "wakes up" and responds by transmitting its unique ID number back to the reader. The reader then sends the number to a computer system.

There are different ways in which tags and readers can communicate. In order to be able to "speak" to each other, tags and readers must follow the same set of standards, of which there are many. Not every reader can communicate with all types of tags.

Tags vary in size, depending mainly on the antenna. They can be very small and can be built into products or into labels which are attached to a product. Other tags are as big as the palm of one's hand and are attached to containers or pallets of goods. Some tags contain a great deal of information, others only a unique ID number.

The Electronic Product Code (EPC) is a set of identification coding or numbering standards. Unlike the bar codes commonly used to distinguish a can of soup from a box of chocolate chip biscuits, the EPC can identify a specific can of soup or box of biscuits by its unique ID number. The EPC contains no personal information. Some experts believe that in years to come the EPC – together with RFID – will be as common as the barcode is today. In fact, it is often called the "next-generation barcode".

No, companies are using and developing a variety of RFID technologies. Some RFID applications rely on active battery-powered tags that send out signals on their own. Other applications use passive tags. These are activated by a stationary or mobile reader and therefore do not need their own energy source. In general, no matter what type of hardware is deployed, RFID uses radio frequency signals to communicate with and identify tags. The frequency used will influence the read distance and speed. Near-Field Communications (NFC), for example, is also based on RFID. With this technology you will be able to buy a tram ticket using your mobile phone. The frequency used and  the way in which the reader in the mobile phone talks to a NFC tag are specific. NFC readers can talk to NFC tags, but not to other types of tags.

The EPC is used for numerous RFID applications, including many in the retail, logistics and pharmaceutical sectors. Companies often tag shipping containers and pallets to track products from the manufacturer to the warehouse and retail outlet. However, other common RFID applications, such as building access cards or electronic passports, use RFID but not normally the EPC. The designer of an RFID application decides whether or not to use the EPC. Since it is already established as an industry standard, many companies in a wide variety of sectors opt to use the EPC to boost efficiency in their supply chains.

The chips in the tags can have all sorts of information on them, depending on the purpose for which the tags are used. The EPC does not contain any personal information. Just as with barcodes today, the EPC can be linked to a secure database in which additional information is stored. The current barcode basically contains the name of the manufacturer and the type of product. The EPC not only indicates the name of the manufacturer and the type of product: it also has a serial number and an indicator showing whether the tagged object is a case of items or an individual item. When linked to databases, it can provide additional specific product information, such as date of manufacture and expiration or the colour or flavour of a specific product. This makes it possible to identify items uniquely.

Items that are tagged with chips that carry the EPC are marked with the EPC symbol. Usually, the symbol  is on the removable packaging or integrated into a product label. The logo means that the manufacturer of the product has agreed voluntarily to disclose the use of RFID. But more than that, the EPC symbol means that the retailer has agreed to adhere to voluntary guidelines relating to consumer privacy. According to these guidelines, consumers should be given:

• Notice if EPC technology is being used
• Choice of different options for discarding or removing the EPC tag after purchase
• Education about EPC technology and its uses

In the case of other uses of RFID without EPC, customers can be informed that it is in use by reading a sign in a store or checking product labels, contracts or user agreements.

This scenario is quite unlikely. You must have an EPC-compliant reader close to the tagged product and personal access to a secure database to call up and interpret all the information related to the identified product.

EPC tags do not contain, collate or store any personal information. The EPC has no power source and can only transmit its unique number if it is less than about 3 meters (10 feet) from a reader that activates the tag. The power – or strength – of readers is strictly regulated by law. The actual distance from which an EPC tag can be read may in fact be shorter, because barriers such as furniture, shopping bags or other obstructions – such as the presence of metal objects – weaken the reader’s signal.

As with the barcode today, personal data can be connected to the EPC. If you use your shop's loyalty card to qualify for discounts or collect points, the shop can link the EPC of the items you purchase to your account in order to send you suitable information about promotions. In addition, as with any non-cash transaction today, quite apart from an EPC tag or bar code the retailer must still capture – if only temporarily – the information required to complete the transaction. However, there are laws about how this information can be used, and it cannot be shared among organisations without your consent or without applying all the relevant legal safeguards.
Nothing prevents the use of anonymous purchasing such as using cash; this capability is not affected in any way by the use of EPC.

In most cases, you will find the EPCglobal symbol if a manufacturer has used EPC-based RFID on the product you have purchased. The EPC tag is usually attached to disposable packaging that you will remove once you unpack the item or it is placed on the product’s label. In some cases, a sales assistant in the shop might remove or deactivate an EPC tag at the cash desk, just as security tags are removed on DVDs or clothes. In any case, you will be informed about all the options available to you.
EPCglobal stipulates that consumers must be informed about the choices available as far as discarding or removing tags is concerned. As the technology develops, you may be able to deactivate EPC tags yourself, or you may simply choose to leave tags on goods to make their return easier in case a recall or return is necessary.

RFID is a wireless technology that relies on a network of fixed and mobile readers and tags, relaying information with radio frequency (RF) signals. While the larger-scale deployment of RFID is relatively new, the use of other radio frequency based wireless technologies is already widespread: television, FM radio, mobile phones…  While there has been concern about the possible negative health impact of RF, a large number of studies about exposure to radio frequency have been carried out over the past few . To date the results of these studies provide no consistent or convincing evidence of a causal relationship between radio frequency exposure (within safety limits) and any adverse effect on health.  Scientists and regulators, however, are continuing with their research programmes and continually re-examining their findings.

Radio frequency exposure is regulated; safety limits are set in both national and international regulations for operating radio frequency equipment  in the workplace environment and in public and residential environments.