@import function is used to import CSS rules from other Style Sheets in HTML documents or it is used to add extra rules within CSS files. This function makes it possible to include external CSS files in a document. CSS @import is used to import CSS Rules from another Style Sheets
Use of @import rule on Internal Style Sheet.
<style>
@import url('style.css');
</style>
@import on external Style Sheet
<style>
@import '/tdb-style.css';
@import 'https://fonts.googleapis.com/css?family=Lato';
</style>
This code will import a CSS file named tdb-style.css and a font family from the specified google font's link.
<!DOCTYPE html>
<html>
<style>
@import url('style.css');
</style>
<!--Body-->
<body>
<button type="submit" class="tdb-school">
Press
</button>
</body>
</html>