You can add borders to elements for decoration, or to make them stand out.
Select the wanted Element by clicking on it to open the Element Editor
Go to the Advanced tab
In the Advanced Tab you can see categories that refer to an element
Wrapper is a constant category and its function is for containing all the elements on a page that aren't header and footer. Other categories depend on the element parts.
Choose a part of element you wish to add borders to
In this example we will use “Image”
Choose “Border” category
Style accordingly and publish 🚀