The document discusses using a GSM-based system to remotely control home and industrial appliances from anywhere via mobile phone. GSM is a digital cellular network available globally that also enables digital data services. The project uses sensors to detect abnormalities and send alerts to a user's phone via a GSM modem connected to a microcontroller. The user can also send SMS messages to control devices connected to the system, like lights or fans, and receive a response about their status.