how to attach font in css code example

Example 1: import font css

@font-face {
  font-family: "Open Sans";
  src: url("/fonts/OpenSans-Regular-webfont.woff2") format("woff2"),
       url("/fonts/OpenSans-Regular-webfont.woff") format("woff");
}

Example 2: how to link fonts css

@font-face {
  font-family: myFirstFont;
  src: url(sansation_light.woff);
}

div {
  font-family: myFirstFont;
}
/*Name the font-family and link the font file in the @font-face rule*/

Example 3: how to link fonts css

@import url(//fonts.googleapis.com/css?family=Open+Sans);
/*When not hosting on my own server use the @import rule which is Google Fonts Versionn and hosted on their server*/