Digital epidemiology is the science of using digital tools and sensors like the internet and smartphones to conduct epidemiological studies. It allows for real-time monitoring of disease trends like influenza outbreaks by analyzing data on people's online searches and movements. Examples of digital epidemiology include using mobile network data to track population movements after disasters, and analyzing search engine queries and social media posts to detect influenza epidemics. Researchers have developed several online tools that use these techniques and are studying topics like vaccination confidence through digital epidemiology.