This is a special type of input developed by Apple and not approved by the W3C. If you use it, it works fine on browsers that don't recognize it.
<input type="search" name="q" />
There are other parameters, including domain name and search results so the user can use their search history. Google for how to use those.
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…