Note the dependencies shown by the lines and arrows (called predecessors, in this example).
Note how diamonds are used to signify milestones which have no duration or effort.
Search the web for a definition of these three terms - milestone, schedule development, and Gantt chart. Post one of the definitions in a WEnote. Post your comment below and then look on the course feed page to see what others have posted.
Note: Your comment will be displayed in the course feed.