Understanding Gantt Chart Terms

Many of the elements, such as titles and labels, available on conventional chart like the bar chart are also available on the Gantt chart. The following terms apply specifically to Gantt charts:

Field or Control	Description
Activity or Task	See Task.
Baseline	A point-in-time snapshot of the project plan that allows the user to identify how the project plan has changed since that point in time.
Data area	The part of the chart that graphically shows the span of dates that each task (or activity) covers. (This area is the right side of the displayed chart.)
Dependencies	A relationship between one task and other tasks that drives when tasks can begin and end. A dependent task cannot start before the task it is dependent on is either started or completed (depending on business rules defined in the application).
Milestone	A specialized mark on the chart that names a meaningful point in time.
Resource	A source of supply or support that is assigned to work on an activity or task.
Task or Activity	In a Gantt chart, each row (task or activity), is represented in the y-axis of the chart, and the span of dates for each row is displayed on the x-axis.
X-axis	The x-axis displays dates that are spanned by items in the y-axis.
X-axis labels	The part of the chart that lists the time scale. The x-axis labels support multiple levels of granularity: second, minute, hour, day, week, month, year.
Y-axis	The y-axis is the display of tasks or activities, and is displayed as rows.
Y-axis labels	The part of the chart that lists activities and their attributes. Activities are shown hierarchically, and subtasks can be hidden or displayed by expanding or collapsing higher level tasks.