A digital assistant, also called a virtual assistant, is an application program that can understand natural language and complete electronic tasks for the end user. Such tasks, which might have been performed by a personal assistant or secretary in previous decades, include taking dictation, reading text or email messages aloud, looking up phone numbers, anticipating requests, placing calls and reminding the end user about appointments. Popular digital assistants currently include Apple's Siri, Google Now and Cortana, the digital assistant built into Windows Phone 8.1. Today's digital assistants are programmed with artificial intelligence, machine learning and voice recognition technology. As the end user interacts with his digital assistant, the AI programming uses sophisticated algorithms to learn from data input and become better at predicting the end user's needs. Tomorrow's digital assistants will be built with more advanced cognitive computing technologies which will allow a digital assistant to understand and carry out multi-step requests and perform more complex tasks such as making a plane reservation. Digital assistants can be contrasted with another type of consumer-facing AI programming called smart advisors. Smart advisor programs are subject-oriented, while digital assistants are task-oriented