The technology that underlies the development of virtual assistants includes advanced artificial intelligence (AI) and natural language processing (NLP). Virtual assistants like Siri, Alexa, and Google Assistant use these technologies to understand and respond to voice commands intelligently. AI algorithms power the learning and adaptation capabilities of these assistants, allowing them to improve over time based on user interactions. NLP enables the assistants to comprehend human language nuances, facilitating a more natural and efficient conversation between the user and the device.