An "observer" is a person or device that watches or monitors events, actions, or phenomena. In scientific contexts, observers play a crucial role in experiments, as their presence can influence outcomes. They gather data and provide insights based on what they see, helping to understand various situations. In everyday life, an observer can be anyone who takes note of their surroundings, such as a bystander at an event or a scientist studying wildlife. Observers can also be represented by tools like cameras or sensors, which capture information without human intervention, allowing for objective analysis.