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.

CSS Selectors
CSS selectors are used to “find” (or select) HTML elements based on their element name, id, class, attribute, and more.

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

You can select all

elements on a page like this (in this case, all

elements will be center-aligned, with a red text color):

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