Which structure is true in terms of using Media Query? code example

Example 1: media query in html style

span { background-image: url(particular_ad.png); }

@media (max-width: 300px) {
    span { background-image: url(particular_ad_small.png); }
}

Example 2: media query methods

1. @media print
{
p
{
font-family: georgia,montserrat;
}
}
2. <link rel="stylesheet" media="screen"
href="/css/screen_version.css">
3. @import "screenstyles.css" screen;