distinguishing bitmap fonts from TrueTypes - from two Windows samples

If you double-click on the font icon, both kinds show you whatever pangram (sentence with all the letters of the English alphabet) your system is programmed with; you see rather clearly how the the bitmap font doesn't work at the 'wrong' sizes - indeed the display doesn't even enlarge the sample after 36 pt. - while the TrueType is shown more-or-less equally effective at seven different sizes, though here without the soft edges of font-smoothing/anti-aliasing.
How and when does anti-aliasing work under Windows?