What are the different types of keypads found on cell phones?

there are basically 3 types of keypads:

1. Tactile keypads - the numeric keypads available conventionally in old cell phones. there are only 12 keys on keypad i.e. numbers 0-9 and # and *. you can type alphabets by pressing each key continuously for the desired number of time.

2. QWERTY keypads - similar to an alpha numeric keyboard with a key assigned for each of the number and alphabetic digit. more useful for texting and browsing.

3. Touch Screen keypads - they are available in most of the high end cell phones where user can interact with the phone using touch screen technology. both of the tactile and qwerty kinds are available in touch screen.