The search form tab allows you to control the way listings are searched. You can choose what search facets to use, and reorder them with drag & drop.
There are two sub tabs in the Search tab, named “Advanced Form” and “Basic Form”. Advanced form is a more detailed search form, usually consisting of 4+ different search facets, and it appears on the listings explore page. While the “Basic Form” typically has 2-3 facets, and it can be used as a widget to be displayed in the homepage.