Final answer:
NFC (Near Field Communication) is the wireless technology with a transmission range of less than two inches, used in credit cards and passports, and is slower than Bluetooth and Wi-Fi.
Step-by-step explanation:
The wireless communication technology described as having a very limited transmission range of less than two inches, used with credit cards and passports, slower than other wireless technologies, and which constantly emits a signal, is NFC (Near Field Communication). NFC technology enables two devices to communicate with each other by bringing them into close proximity, which is a security feature for transactions. This technology operates on microwave frequencies, similar to those used by RFID (Radio Frequency Identification), although RFID typically has a longer range. Both NFC and RFID are used for different purposes compared to other wireless technologies like Bluetooth and Wi-Fi, which have broader range and are suited for different types of communications.