DTMF - Dual Tone Multi Frequency. A DTMF keypad is a standard accessory on most modern radios. When a DTMF key is pressed along with the P.T.T. key, a two tone sound is transmitted. A receiver with a DTMF decoder can convert the tones back into an electronic command. Dual - Two.
Some radios can operate on two different bands.
It is called a dual band radio. Some radios have two VFO modes. It is called dual VFO's. Duplex - Transmission and reception on different frequencies. Repeater operation requires simultaneous reception and transmission.