Check out example codes for "html in page navigation". It will help you in understanding the concepts better.

Code Example 1

Uses HTML's anchors:
<a href="#anch_start">INTRO</a>
<a href="#anch_end">ENDING</a>

'href' uses 'id' to find these segments:
<div class="intro"  id="anch_start"></div> 
<div class="epic_ending"  id="anch_end"></div>

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