<html>
<head>
<meta charset="utf-8">
</head>
<body>
<p>
<input type="radio" name="color">
<input type="radio" name="color">
<input type="radio" name="color">
</p>
<p>
<input type="radio" name="color2">
<input type="radio" name="color2">
<input type="radio" name="color2">
</p>
</body>
</html>- 같은 name 끼리 묶임.
<input type="checkbox" name="color2">
<input type="checkbox" name="color2">
<input type="checkbox" name="color2">