Display Templates are used with CSWP to format/style search result generated by CSWP search query. Display Templates control which managed property is shown in the search results and how they appear in the Web Part. Each Display Template has two files: an HTML version of the Display Template that you can edit in your HTML editor, and a .js file that is for SharePoint use and should never be modified. CSWP uses combination of two Display Templates, Control Templates and Item Templates to render results. Item Template provides HTML that determines how each item in the result set is displayed. For example, the Item Display Template might provide the HTML for a list item that contains a picture, three lines of text that are mapped to different managed properties associated with the item. The Item Display Template is rendered one time for each item in the result set. So, if the result set contains ten items, the Item Display Template creates its section of HTML ten times.