The DES collaboration is one of the largest imaging galaxy survey carried out, that recently finished observations of more than 300 million galaxies over 5000 square degrees of the Southern sky, in five photometric bands, and up to redshift ~ 1, when the Universe had half its current age. The primary mission of DES is to investigate cosmic acceleration and dark energy. I will summarise the complex analysis and the cosmology results from the first three years of data (DES Y3), using the study of the large-scale structure in the universe, combining galaxy clustering and weak gravitational lensing, and from geometric probes, such baryon acoustic oscillation and supernovae type Ia.