how to use @font-face css code example

Example 1: how many fonts can i add in a css font-face

@font-face {
    font-family: CustomFont;
    src: url('CustomFont.ttf');
}

@font-face {
    font-family: CustomFont2;
    src: url('CustomFont2.ttf');
}

Example 2: @font-face rule in css

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