CSS

open sans css

/* copy paste it in your .css file*/
@import url("https://fonts.googleapis.com/css2?family=Open+Sans:wght@300;400;600;700;800&display=swap");

/* copy paste it in your .html or .php file*/
<link href="https://fonts.googleapis.com/css2?family=Open+Sans:wght@300;400;600;700;800&display=swap" rel="stylesheet" type="text/css">

open sans font

//This is from google fonts
// to use import 
@import url('https://fonts.googleapis.com/css?family=Open+Sans');
//to use link in head tag
<link rel="preconnect" href="https://fonts.gstatic.com">
<link href="https://fonts.googleapis.com/css2?family=Open+Sans" rel="stylesheet">

font family Open Sans

<link href="https://fonts.googleapis.com/css?family=Open+Sans:400,600,300" rel="stylesheet" type="text/css">

open sans font

<link href="https://fonts.googleapis.com/css?family=Open+Sans:600,800" rel="stylesheet">