The difference between ID selector and class selector

1、ID Selectors
ID Selector use # Are identified , Follow closely the next year ID name
grammar ：
ID Selectors
id name { Property name 1： Property value 1; Property name 2： Property value 2; Property name 3; Property value 3;}
label
< p id=“id name ”>< /p>
Elemental ID Value is unique , It can only correspond to one element in the document .
Usage is basically the same as class selector
2、ID The difference between a selector and a class selector
w3c The standard stipulates , In the same page content , It is not allowed to have the same name id The object appears , But the same name is allowed class
Class selectors （class） It's like a person's name ,, It can be used multiple times
ID Selector is like a person's ID number , All China is the only , Don't repeat