A trailer is a non-motorized freight transport vehicle attached to a truck or other motorized vehicle for hauling cargo. Trailers may be used to carry everything from landscaping materials to animals to construction equipment and machinery. Some trailers are specifically designed to be driven on the highway while others require off-road operation and may be more suitable for use on unpaved or gravel roads. There are a variety of trailers available, including dump trailers, pintle hook trailers and equipment trailers. A wide range of trailers can be found at any home improvement store, or online.

In filmmaking, a trailer (also known as a preview or teaser) is a short clip that provides an overview of the story and highlights the main characters of a feature film. Often, trailers are a key part of a marketing campaign for a new release and are designed to attract audience interest in a movie and increase ticket sales. In addition to their traditional theatrical screening, film trailers are also distributed on the internet and in television commercials.

As the ubiquity of video sharing and social media has increased, the popularity of trailers has grown as well. Film makers now produce trailers for their movies in a wide variety of formats, from short clips to full-length trailers. In some cases, the same scene can appear in multiple different trailers, depending on the needs of each medium and audience.

In the early days of cinema, trailers were used as a form of pre-show entertainment before the feature film was shown in a theater. They were often accompanied by a musical number or a comedy sketch. Many classic trailers were produced in this era, including Alfred Hitchcock giving viewers a guided tour of the Bates Motel and finally opening the shower curtain to reveal Vera Miles screaming in horror in the iconic Psycho trailer.

Today, the majority of trailers are created for major Hollywood releases and often include the official studio logo. They are regulated by the Motion Picture Association of America, who oversees the rating system for films and trailers. Many modern trailers are also synchronized with their soundtrack, and some feature music that will not be included in the final film’s soundtrack. Historically, the composer of a film’s score would work closely with the producer and director to create the music for the trailer.

Aside from introducing the film’s plot, characters, and key scenes, most trailers also aim to convey a general tone or genre. They usually feature a blend of dialogue and music, and can sometimes include voiceover narration. The emergence of the digital age has made it possible to include special effects in trailers, as well as to combine footage from different takes of a key scene.

In order to be effective, trailers must be kept relatively short and enticing while still providing enough information about the film to attract audience interest. This is difficult, as the trailer must provide a sense of what the viewer will experience when they see the feature film. To do so, the trailer should start slowly and tensely, and build to a climax that is both emotional and high stakes.