Siri is a virtual assistant created by Apple Inc. that uses voice recognition technology to help users perform tasks on their devices. It can answer questions, set reminders, send messages, and provide information about the weather, among other functions. Siri is available on various Apple products, including the iPhone, iPad, Mac, and Apple Watch. Siri uses artificial intelligence to understand and respond to user commands. It can learn from user interactions to improve its responses over time. Users can activate Siri by saying "Hey Siri" or by pressing a button, making it a convenient tool for hands-free operation.