SAP UI 5 image library

I had look at the demo apps built by SAP .

sap.m Explored

<IconTabBar
id="idIconTabBarMulti"
expanded="{device>/isNoPhone}">
<items>
<IconTabFilter
icon="sap-icon://hint">
<Text text="Info content goes here ..." />
</IconTabFilter>
<IconTabFilter
icon="sap-icon://attachment"
count="3">
<Text text="Attachments go here ..." />
</IconTabFilter>
<IconTabFilter
icon="sap-icon://notes"
count="12">
<Text text="Notes go here ..." />
</IconTabFilter>
<IconTabFilter
icon="sap-icon://group">
<Text text="People content goes here ..." />
</IconTabFilter>
</items>
</IconTabBar>

If i want to reuse the images of these demo applications , how do i do it??

Where are these images actually present ?

Generally we give the relative path of location of the image within our application .

What does the sap-icon://group uri mean??

Can somebody explain how this uri is constructed ?