What is TPIN or MPIN? How do I get it?

What is TPIN or MPIN? How do I get it?

TPIN is authorisation code that is sent to via CDSL (Securities Depository) your registered mobile number and email address at the time of your demat account creation.

Similarly, MPIN is the code sent to you via NSDL. 
Incase, you forget your TPIN or MPIN, you can use the 'Forgot' option on their website to regenerate your code.