"To create a trailer" means to produce a short video that gives a preview or highlights of a longer film or project. It is like a sneak peek or teaser to generate interest and attract an audience. Full definition
The medium doesn't suit every type of book, so take a look at what your competitors are doing and see if the cost of creating a trailer makes sense for you. (blog.reedsy.com)
Creating a trailer doesn't have to be particularly complicated or expensive. (susandaffron.com)