html map标签是什么？html map标签的结构及具体使用方法详解

<div class="map_img">

    <img class="mapImg" usemap="mapName" src="isphoto/abc.png" alt="" style="width: 450px">

    <map name="mapName">

         <area shape="circle" coords="633,276,28" target="_blank" href ="javascript:alert('汽车图标');" alt=""/>

     </map>

    <!-- 一张图片对应一个name和usemap -->

    <img class="mapImg" usemap="mapName2" src="isphoto/abc.png" alt="" style="width: 450px">

     <map name="mapName2">

         <area shape="circle" coords="633,276,28" target="_blank" href ="javascript:alert('第二张图的汽车图标');" alt=""/>

     </map>

</div>

<img src ="planets.gif" alt="无法显示此图像" usemap ="#planetmap" />

<map id ="planetmap" name="planetmap">

<area shape ="rect" coords ="0,0,82,126" href ="sun.htm" alt="Sun" />

<area shape ="circle" coords ="90,58,3" href ="mercur.htm" alt="Mercury" />

<area shape ="circle" coords ="124,58,8" href ="venus.htm" alt="Venus" />

</map>