This system allows users to verify their phone numbers using Twilio Voice, PHP 7, MySQL 5.x, and jQuery. The process involves the user entering their phone number on a web page, generating a random verification code, and receiving a call with instructions to enter the code. If the entered code is incorrect, the user is prompted again until they enter the correct code. Once the code is verified, the system updates the database and displays a success message to the user. The entire process is handled through AJAX requests to Twilio's REST API, which initiates phone calls and gathers the user's input using TwiML.