The Timeline uses a series of ‘Periods’ graphically displayed as Arrow bars.

Within each Period, there are ‘Events’ graphically displayed as pale dots within the bars.
In this example, Period 1 has 2 Events, Period 2 has 3 Events, Period 3 has 4 Events and Period 4 has one event.

Each of these interactive elements displays a new panel of content when clicked.
As the Timeline suggests, the idea is to explain a progression of something: growth, worsening conditions etc.

Example: worsening frailty: each dot can describe a worsening symptom/feature of the condition.