A CSS comprises of style rules that are interpreted by the browser and then applied to the corresponding elements in your document. A style rule is made of three parts −
Selector − A selector is an HTML tag at which a style will be applied. This could be any tag like <h1> or <table> etc.
Property − A property is a type of attribute of HTML tag. Put simply, all the HTML attributes are converted into CSS properties. They could be color, border etc.
Value − Values are assigned to properties. For example, color property can have value either red or #F1F1F1 etc.
You can put CSS Style Rule Syntax as follows −
selector { property: value; }
Example − You can define a table border as follows −
table{ border :1px solid #C00; }
Here table is a selector and border is a property and given value 1px solid #C00 is the value of that property.
The id selector selects the id attribute of an HTML element to select a specific element. An id is always unique within the page so it is chosen to select a single, unique element.
It is written with the hash character (#), followed by the id of the element.
Let?s take an example with the id “para1”.
The class selector selects HTML elements with a specific class attribute. It is used with a period character . (full stop symbol) followed by the class name.
Let’s take an example with a class “center”.
The universal selector is used as a wildcard character. It selects all the elements on the pages.