CSS (Cascading Style Sheets)
CSS is used to describe the HTML elements look like on the web page and how the HTML elements are to be displayed on the screen, paper, OR another media. HTML stands for "HyperText Markup Language" and it is a stander markup language for a web page.
Use of CSS in HTML
CSS is used to give an effective and attractive design of HTML elements. If we are using only HTML code to design a web page then it's not more attractive BUT when to apply some CSS properties on HTML elements then it's looking good and is more flexible.
Example: CSS in HTML
<p>This is the 1st Paragraph</p> //p element look normal
OUTPUT - This is the 1st Paragraph
Supposed, Apply some CSS properties on <p> element:
p {font-family: italic;}
Example With CSS Properties
<p>This is the 2nd Paragraph</p> // p element look like with CSS properties
OUTPUT - This is the 2nd Paragraph