console frame buffer font is just a fancy way of saying pixel font.
console means that it is to be used with a console [1] or terminal emulator[2]. Traditionally terminal emulators used bitmap fonts, but modern versions support vector fonts as well. frame buffer [3] just means that it is a bitmap font like the ones used in traditional frame buffer consoles.
It's referring to a kind of display driver in which frames are rendered as bitmaps into memory then that bitmap will be rendered to a screen. Fonts for such drivers are, AFAIK, always bitmap fonts.
