$|V_{ud}|$, $|V_{us}|$, $|V_{cd}|$, $|V_{cs}|$ and charm (semi)leptonic decays: WG1 summary from CKM 2016

We summarize the current status of the determination of the CKM matrix elements |V_ud| and |V_us|, which is at the precision frontier of CKM phenomenology. We also review recent progress on the study of charm (semi)leptonic decays, and the determination of |V_cd| and |V_cs|.