Selectors play a major role in CSS, there are multiple types of selectors.

Selectors

CSS selectors define the pattern to select elements to which a set of CSS rules are then applied.70% gain in css is all about selecting the elements.

CSS selectors can be grouped into the following categories based on the type of elements they can select.

1. Universal Selector

This selector are use to style all the tags in the body.

*{
    background-colour:red;
}

2. Individual Selector

In this selector, you can address any individual element for ex. if I selected P tag to style it will select all the paragraphs of the web page where it will in a list or div.

p{
background-colour:red;
}

3. Class & ID selector

In this selector, you can select a particular ID and class. for selecting any class use (.) dot. and for selecting any Id use (#)pond.

<ul>
<li class="Warning"> Test</li>
<p id="denger"> this is my para</p>

.warning{
background-colur:green;
colour:white;
}
#danger{
colour:blue;
}

Note: when you want a uniquely identified element => Use Id, otherwise use class.

4. And selector

if you want to target a particular class in the tag 'and' selector we use. also called chain selector.

<ul>
    <li class="text-white background"> Text-1</li>
</ul>

li.text-white.background{
colour:orange;
}

5. Combine Selector

In one CSS code, if you want to target more than one tag by the use of commas as a combine selector it is possible.

span,li{
background-colour:green;
}

6.Inside an element

For styling elements inside the element, this selector is use.

<div>
    <div>
        <p>This is my para</P>
    <div>
<div>

div div p{
     colour:green;
}

7. Direct child

If you want to style element after element like parent-child form. direct child selector is use.

div>li{
    background-clour:green;
}

8. Sibling (~ or +)

if you want to select an element just after the class name use +or~.

<p class="sub"> Test 1</p>
<p> Test-2 </p>

.sub +p{
    background-colour:red;
}

In this code, Text-2 will be targeted.

9. nth child selector

In this selector we can select the perticular pattern of the element to style i.e odd, even, every fifth etc.

Li:nth-child(2n){
    bacakground-colour:green;
}

In nth-child we have first-child and last-child selector.

10. Psudo Selector

• :: before

  In CSS, ::before creates a pseudo-element that is the first child of the selected element. It is often used to add cosmetic content to an element with the content property. It is inline by default.

<q>Some quotes</q>, he said, <q>are better than none.</q>

q::before {
  content: "«";
  color: blue;
}

q::after {
  content: "»";
  color: red;
}

Output :

• ::after :

  In CSS, ::after creates a pseudo-element that is the last child of the selected element. It is often used to add cosmetic content to an element with the content property. It is inline by default.

<p class="boring-text">Here is some plain old boring text.</p>
<p>Here is some normal text that is neither boring nor exciting.</p>
<p class="exciting-text">Contributing to MDN is easy and fun.</p>

.exciting-text::after {
  content: " <- EXCITING!";
  color: green;
}

.boring-text::after {
  content: " <- BORING";
  color: red;
}

Output:

This is all about selector and types of selector. Hope you like it

Thank You !