Both of these apps are installed and function in similar ways. Both will allow you to set up a kind of product customizer that will allow the customer to choose different selections and options that will or will not add a price to the product. Both also allow for steps and options to be conditional on prior selections.
Builder does this by creating its own custom product page for the product to be customized with a pretty structured, step by step customization process. The steps are essentially groups of selections that a customer will choose from where they have to proceed through one at a time and make a selection. Builder allows for the use of images with each selection, and a separate preview image can be displayed based on the combination of builders selections. Builder will allow for the main price on that builder page to be adjusted by selections.
Options uses a more fluid and unstructured product customization process. Options are created and then paired with products in the form of relationships. The same options can be used with multiple products You have more control over how selections for options are made, whether it be in the form of a dropdown menu or radio buttons. Options will not allow you to have pictures associated with your options and the options are set up directly on Shopify's product pages. Options adds its priced options as a kind of add on to the main product price and while the add on price is visible on the main page it will not change the main product price on the product page without a custom modification.