There are 2 types of digital broadcasts available currently - Standard Definition (SDTV) and High Definition (HDTV). SD is the most basic form of digital television and has clearer pictures than analogue TV as well as widescreen 16:9 aspect ratio, extra channels and digital sound, but doesn't offer any additional resolution. HDTV does offer increased resolution, however, with up to five times as much detail as SDTV.