title: Yocto: Difference between CORE_IMAGE_EXTRA_INSTALL and IMAGE_INSTALL
body: <p>Recently, I tried to include open source package (iperf3) to target image via Yocto build. (Updating local.conf for <code>IMAGE_INSTALL += &quot;iperf3&quot;</code>, as the project already corresponding recipe).
  But the final image did not include in root file system.</p>
  <p>I tried the same by adding to package group recipe in <code>&lt;DistroMetaLayer&gt;/recipe-core/packagegroups/RDEPENDS_packagegroup*</code> and was able to include it successfully.</p>
  <p>Can someone provide me explanation for the behavior.</p>