Packet switching is a method used in computer networks to send data in small, manageable pieces called packets. Each packet contains a portion of the data, along with information about its destination. This allows multiple packets from different sources to travel through the network simultaneously, optimizing the use of available bandwidth. When packets reach their destination, they are reassembled in the correct order to form the original message. This technique is efficient and robust, as it can adapt to network congestion and failures. The Internet primarily relies on packet switching to facilitate communication between devices worldwide.