There are three achievement levels, A, AA, AAA.
Level A includes "1.1.1 Non-text Content (which is not text, it is not subject to the screen reader of the visually impaired, and the visually impaired can not acquire any information unless special consideration is given)" and "2.1.2 No Keyboard Trap (If you create content that can not be accessed at all with the keyboard, it may interfere with users who can only use the keyboard)" "2.3 Seizures (If you have content that flashes on the page, Some users may cause symptoms of epilepsy) ", so to speak," success criterions achievement that should be considered at the minimum "is gathered.
For level AA, level A is difficult to deal with in terms of budget and man-hours, but items that should be dealt with are added. For example, it will be required to give captions to live videos such as weather forecast (1.2.4), and to give recorded description (1.2.5) to recorded videos.
For level AAA, it is required to take considerable sophistication such as giving sign language to recorded videos (1.2.6) or considering using difficult words (3.1.3 and 3.1.5). It is not recommended to target this level as a general policy.