Behavior refers to any activity or action that living organisms engage in, which can be observed, measured, and analyzed. It encompasses all interactions an organism has with its environment, including both overt (observable) and covert (internal) actions.
Example
A student raising their hand to ask a question in class is an example of behavior. It is an observable action that occurs in response to a specific environmental stimulus (the teacher asking if anyone has a question) and can be measured by how frequently the student raises their hand in class.