basic commented picture of an arrow

arrow.svg

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" version="2.0" viewBox="0 0 10 10" id="svg819">
<defs>
  <!-- isoceles triangle is positioned with its base's center on 0 0 -->
  <polygon points="-2,0 2,0 0,4" id="arrowhead" />
</defs>
  <g>
    <!-- path from (0, 0) to (5, 5) -->
    <path d="M 0,0 5,5" style="stroke:#000000" id="arrowspline" />
    <!-- move arrowhead to (5, 5):, and rotate with -45 degrees, with origin point being at 5, 5-->
    <use xlink:href="#arrowhead" x="5" y="5" transform="rotate(-45, 5, 5)" />
  </g>
</svg>