radio button group labels and label

1.html in how the rules for a group of radio buttons?

They set the name attribute of a name on it.
<input type = "radio" name = "aaa"> M
<input type = "radio" name = "aaa"> female

2.label label
2.1for associated
<label for = "email"> E-mail: </ label >  
<the INPUT of the type = "text" the above mentioned id = "Email">  
 label tag is an extension of his form controls associated with that mouse click on him, there will be the same as the form and click on the associated controls his effect. This premise is the label for the attribute value of the id attribute of the form control you want to associate the same.
2.2 If not want to use the second method can also be used for id and association.
<pre> <pre name = "code" class = "HTML">
<label> E-mail: <INPUT type = "text"> </ label>  
the effect is the same as before.