This explains what basic dimensions are, what they are used for, and how they are indicated to the user. See my playlist of other definitions here: https://youtube.com/playlist?list=PL37yq0C_XXoycVR3EqmTTIXvIbOWumTJo&si=psqt2ZJ39Mee0aRz
Right-click 'Download' and select 'Save Link As' if the file opens in a new tab.
