Everyone loves Sitecore caching capabilities, especially HTML Caching, where you can cache the output HTML of any rendering.
On rendering definition item, Set 'Cacheable' checkbox On item presentation details, Select your rendering and set 'Cacheable' checkbox. The problem with the first approach is that once you set the 'Cacheable' option on definition item, any page that uses this rendering will always cache it, and you can't cancel the caching for that rendering on some pages that you dont want it to be cached there.