code标签的用途是什么？代码片段如何展示？

<pre class="brush:php;toolbar:false"><code>以同时保留格式并赋予语义；3. 配合css设置等宽字体、背景色和溢出滚动提升可读性；4. 避免单独使用<code>或多行代码用<div>模拟；5. 通过prism.js等库实现语法高亮；6. 可嵌入codepen或monaco editor增强交互；7. 添加一键复制、行号和diff对比等功能提升用户体验，最终实现清晰、可访问且专业的代码展示。</p><p>@@##@@</p><p><div class="code" style="position:relative; padding:0px; margin:0px;"><div class="code" style="position:relative; padding:0px; margin:0px;"><div class="code" style="position:relative; padding:0px; margin:0px;"><div class="code" style="position:relative; padding:0px; margin:0px;"><div class="code" style="position:relative; padding:0px; margin:0px;"><div class="code" style="position:relative; padding:0px; margin:0px;"><div class="code" style="position:relative; padding:0px; margin:0px;"><div class="code" style="position:relative; padding:0px; margin:0px;"><div class="code" style="position:relative; padding:0px; margin:0px;"><div class="code" style="position:relative; padding:0px; margin:0px;"><div class="code" style="position:relative; padding:0px; margin:0px;"><div class="code" style="position:relative; padding:0px; margin:0px;"><div class="code" style="position:relative; padding:0px; margin:0px;"><div class="code" style="position:relative; padding:0px; margin:0px;"><pre class="brush:php;toolbar:false"><code>