To follow the trail or movements of someone or something, typically in order to find them or note their progress. The hunters tracked the deer through the forest.
To observe or monitor the progress or development of something over a period of time. The scientist tracked the growth of the plants in the experiment.
To record the progress or development of something. The software tracks the user's activity on the website.
To move in relation to something else, often in a parallel or corresponding manner. The camera tracked the actor as he moved across the stage.