Final answer:
A Gantt chart displays the tasks that need to be completed at specific times for a project, with time on the x-axis and tasks on the y-axis. It is distinct from a time series graph, which shows how a variable changes over time, but both use similar axis structures.
Step-by-step explanation:
The chart that shows what tasks must be completed at which times in order to complete a project, with time units on the x-axis and tasks on the y-axis, is a Gantt chart. A time series graph, by comparison, shows how a variable changes over time, with the horizontal axis showing time and the vertical axis displaying another variable, such as the unemployment rate in the United States shown since 1975.
However, time series graphs typically represent data such as price changes, stock movements, or unemployment rates, rather than project tasks and timeframes as in a Gantt chart.
Unlike time series graphs, Gantt charts are specifically designed for project management and are used to illustrate the start and finish dates of the terminal elements and summary elements of a project. Terminal elements and summary elements comprise the work breakdown structure of the project, and using a Gantt chart can help in tracking project schedules, the sequence of tasks, and their respective timelines effectively.