  The third data release of Gaia has provided low resolution spectra for
~100,000 white dwarfs (WDs) that, together with the excellent photometry and
astrometry, represent an unrivalled benchmark for the study of this population.
In this work, we first built a highly-complete volume-limited sample consisting
in 12,718 WDs within 100 pc from the Sun. The use of VOSA tool allowed us to
perform an automated fitting of their spectral energy distributions to
different atmospheric models. In particular, the use of spectrally derived
J-PAS photometry from Gaia spectra led to the classification of DA and non-DA
WDs with an accuracy >90%, tested in already spectroscopically labelled
objects. The excellent performance achieved was extended to practically the
whole population of WDs with effective temperatures above 5500 K. Our results
show that, while the A branch of the Gaia WD Hertzsprung-Russell diagram is
practically populated by DA WDs, the B branch is largely formed by non-DAs
(65%). The remaining 35% of DAs within the B branch implies a second peak at
~0.8 Mo in the DA-mass distribution. Additionally, the Q branch and its
extension to lower temperatures can be observed for both DA and non-DA objects
due to core crystallisation. Finally, we derived a detailed spectral evolution
function, which confirms a slow increase of the fraction of non-DAs as the
effective temperature decreases down to 10,500 K, where it reaches a maximum of
36% and then decreases for lower temperatures down to ~31%.
