A Gantt chart is a project scheduling tool used to plan and track tasks and milestones. It displays tasks, or activities, as horizontal bars against a calendar timescale, allowing visualization of schedules and dependencies. Key elements shown on a Gantt chart include task bars indicating duration, milestones, resources, and dependencies between tasks. An example Gantt chart is provided to illustrate making a cup of tea, showing the tasks, durations, and dependencies between steps.