Apple's virtual assistant that responds to voice commands is named Siri. Launched in 2011, Siri allows users to perform tasks such as setting reminders, sending messages, and answering questions using natural language voice commands. Siri utilizes machine learning and natural language processing to enhance its ability to understand and respond to a wide range of user inquiries. As part of Apple’s ecosystem, Siri integrates with various devices and services, providing users with a seamless and convenient experience.