The Read() application allows you to play a sound prompt to the caller and retrieve DTMF input from the caller, and save that input in a variable. The first parameter to the Read() application is the name of the variable to create, and the second is the sound prompt or prompts to play. (If you want multiple prompts, simply concatenate them together with ampersands, just like you would with the Background() application.) There are some additional parameters that you can pass to the Read() application to control the number of digits, timeouts, and so forth. You can get a complete list by running the core show application read command at the Asterisk CLI. If no timeout is specified, Read() will finish when the caller presses the hash key (#) on their keypad.
In this example, the Read() application plays a sound prompt which says "Please enter the extension of the person you are looking for", and saves the captured digits in a variable called Digits. It then plays a sound prompt which says "You entered" and then reads back the value of the Digits variable.