Why woff format font is displayed on android 4.2?

Question

css

Hello!
I'm reading The Big Book of CSS3 . Got to the "Formatting Text" section . It was said that woff format fonts are not supported by android. I went to the page from a mobile phone under android 4.2 - the font is displayed, everything is fine, like on a PC. Why is that?
Font: Open Sans
Here is the code:
CSS:

@font-face {
  font-family: "Open Sans";
  src: url(fonts/opensans-regular-webfont.woff);
  font-weight: normal;
  font-style: normal;
}

p {
  font-family: "Open Sans";
}

Answer 1

I think Open Sans is one of the android system fonts.

Answer 2

caniuse.com/#feat=woff