CSS selectors are used to select the content you want to style. Selectors are the part of CSS rule set. CSS selectors select HTML elements according to their id, class, type, attribute, etc.

There are several different types of selectors in CSS.

1. Element Selector:

The element selector selects HTML elements based on the element name.

Example

Here, all <p> elements on the page will be center-aligned, with a blue text color: 

p {
  text-align: center;
  color: blue;
}

 

2. Id Selector:

• The id selector uses the id attribute of an HTML element to select a specific element.
• The id of an element is unique within a page, so the id selector is used to select one unique element!
• To select an element with a specific id, write a hash (#) character, followed by the id of the element.

Example

The CSS rule below will be applied to the HTML element with id="para1": 

#para1 {
  text-align: center;
  color: blue;
}

 

3. CSS Class Selector:

• The class selector selects HTML elements with a specific class attribute.
• To select elements with a specific class, write a period (.) character, followed by the class name.

Example

In this example all HTML elements with class="center" will be blue and center-aligned: 

.center {
  text-align: center;
  color: blue;
}

You can also specify that only specific HTML elements should be affected by a class.

Example

In this example only <p> elements with class="center" will be red and center-aligned: 

p.center {
  text-align: center;
  color: red;
}

4. Universal Selector:

The universal selector (*) selects all HTML elements on the page.

Example

The CSS rule below will affect every HTML element on the page: 

* {
  text-align: center;
  color: blue;
}

5.Group Selector:

• The grouping selector selects all the HTML elements with the same style definitions.
• Look at the following CSS code (the h1, h2, and p elements have the same style definitions):

h1 {
  text-align: center;
  color: red;
}

h2 {
  text-align: center;
  color: red;
}

p {
  text-align: center;
  color: red;
}

 

• It will be better to group the selectors, to minimize the code.
• To group selectors, separate each selector with a comma.

Example

In this example we have grouped the selectors from the code above: 

h1, h2, p {
  text-align: center;
  color: red;
}