Timelines give you an overview on what everyone is working on at a specific moment in time. You can sort the timeline by project or by assignee.
The project view shows the length and dates of each task in a project, you can also see to whom the tasks are assigned.
The assignee view takes the assignee as the source, it shows the length and dates of the the projects and tasks but they are now sorted per workspace member. So you can easily see the tasks and projects each team member is working on and what's up next for them.