Style presets allow you to create a reusable set of styles that when changed will update across all blocks using those styles. This is different from smart patterns as style presets do not affect the content of the block.
To create a style preset, go to the style tab of ay block and scroll to the bottom. There you will see the style presets option.
Once you give your preset a name and select the create preset option it will then be available in the list of presets by selecting the ‘user preset’ option.
Once you have selected a preset, any style changes then made to the block while using the preset will be synced with the preset and update across all templates.