Even though the
@font-face rule was born with the CSS2 spec in 1998, it took almost ten years for browser makers to start supporting it – with real, widespread support coming not until a couple of years later.
That is why people usually see it as part of CSS3.
This solution requires you to personally own the license of the fonts you want to use – and to upload them to your server. Being based on self-hosting, it can add to your space and bandwidth fee quite quickly.
But there's an easy solution to that: subsetting.