           v1.12.0.</div>
        </div>

        <a id="ember28109" class="ember-view es-button-secondary old-version-button" href="/release/concepts/index"> Go to v5.0.0 </a>
      </div>

    <div class="article-title">
      <h1>
        Core Concepts
      </h1>

        <a href="https://github.com/ember-learn/guides-source/edit/master/guides/v1.12.0/concepts/index.md" target="_blank" class="edit-page" rel="noopener">
          <img class="edit-icon" src="/images/pen.svg" alt="Edit pencil">
        </a