What is DTMF and why it is used?

Related questions

1. What is a DCS code?
2. What does DTMF mode mean?
3. How many DTMF tones are there?
4. What is the difference between tone and pulse dialing?
5. What is DTMF circuit?
6. What is DTMF in IVR?
7. What is DTMF band?
8. What is DTMF robot?
9. What is Ctcss DCS function?
10. Can you still use old rotary phones?

Tags

1. #switching
2. #commands
3. #telecommunication
4. #frequency
5. #centers
6. #bands
7. #widely
8. #handsets
9. #voice
10. #systems
11. #method
12. #multifrequency
13. #telephone
14. #numbers
15. #issue
16. #lines
17. #analog
18. #signaling
19. #between