---
title: Visual Structure
page_title: Visual Structure
description: This section defines the terms and concepts used in the scope of the __RadTimeline__ control.
slug: radtimeline-visual-structure
tags: visual,structure
published: True
position: 2
---

# Visual Structure

This section defines the terms and concepts used in the scope of the __RadTimeline__ control. They can be helpful when contacting with the support service in order to describe your issue better. Below you can see snapshots and explanations of the main visual elements of the control:

![{{ site.framework_name }} RadTimeline Visual Structure](images/timeline_visualstructure_main.PNG)

* __Visible Viewport__: The rectangular region representing the time span between __VisiblePeriodStart__ and __VisiblePeriodEnd__. 

* __Scrollable Area__: You can use the Resizable ScrollBar or the __SelectionThumb__ to change the visible time span of the Timeline control.

* __Time Ruler__: The area where the time periods are shown.

* __TimelineInstantItem__: The element represent data which happens one in a time.

* __TimelineItem__: This element represent data which happens periodical.

* __Group__: The timeline items in the RadTimeline control can be displayed in groups. The groups can be expanded or collapse.

* __Striplines__: The lines are represented by a __TimelineStripLineControl__ framework control.