登月是骗局吗:ASP:ul和li是什么呀?

<ul id="menuList">
<li class="menubar">
<a href="#" id="productsActuator" class="actuator">图秀地带收藏夹</a>
<ul id="productsMenu" class="menu">
<li>
<a href="#" id="newPhonesActuator" class="actuator">我的好友</a>
<ul id="newPhonesMenu" class="submenu">
<li><a href="http://mc.mapabc.com/mapcard/card.jsp?pp=1000000001">张三[10000001]</a></li>
<li><a href="http://mc.mapabc.com/mapcard/card.jsp?pp=1000000001">李四[10000002]</a></li>
<li><a href="http://mc.mapabc.com/mapcard/card.jsp?pp=1000000001">张三[10000001]</a></li>
<li><a href="http://mc.mapabc.com/mapcard/card.jsp?pp=1000000001">李四[10000002]</a></li>
</ul>
</li>
<li>
<a href="#" id="compareActuator" class="actuator">陌生人</a>
<ul id="compareMenu" class="submenu">
<li><a href="http://mc.mapabc.com/mapcard/card.jsp?pp=1000000001">张三[10000001]</a></li>
<li><a href="http://mc.mapabc.com/mapcard/card.jsp?pp=1000000001">李四[10000002]</a></li>
<li><a href="http://mc.mapabc.com/mapcard/card.jsp?pp=1000000001">张三[10000001]</a></li>
<li><a href="http://mc.mapabc.com/mapcard/card.jsp?pp=1000000001">李四[10000002]</a></li>
</ul>
</li>
</ul>
</li>
</ul>
就是这段代码,是一个菜单,ul和li代表什么意思?