A costume drama or period drama is a period piece in which elaborate costumes, sets and properties are featured in order to capture the ambience of a particular era.
The term is usually used in the context of film and television. It is an informal crossover term that can apply to several genres but is most often heard in the context of historical dramas and romances, adventure films and swashbucklers. The implication is that the audience is attracted as much by the lavish costumes as by the content.
The most common type of costume drama is the historical costume drama, both on stage and in movies.