<svg viewBox="0 0 200 100" xmlns="http://www.w3.org/2000/svg">
  <!-- All geometry properties are relative to the current user space -->
  <pattern
    id="p1"
    x="12.5"
    y="12.5"
    width="25"
    height="25"
    patternUnits="userSpaceOnUse">
    <circle cx="10" cy="10" r="10" />
  </pattern>

  <!-- All geometry properties are relative to the target bounding box -->
  <pattern
    id="p2"
    x=".125"
    y=".125"
    width=".25"
    height=".25"
    patternUnits="objectBoundingBox">
    <circle cx="10" cy="10" r="10" />
  </pattern>

  <!-- Left square with user space tiles -->
  <rect x="10" y="10" width="80" height="80" fill="url(#p1)" />

  <!-- Right square with bounding box tiles -->
  <rect x="110" y="10" width="80" height="80" fill="url(#p2)" />
</svg>