What is B-movie?
B-movie meaning in Information Science terminology / glossary / dictionary is:
A low-budget motion picture, especially one shown as the second half of a double feature during the period when most movie theaters in the United States sold admission to a double feature (example: I Walked with a Zombie  directed by Jacques Tourneur). The main feature, shown first, was generally a large-budget production (A-movie) employing well-know actors. The term is still used although the practice of showing two films for the price of a single admission has been discontinued in most theaters. B-pictures typically use less well-known actors and may have limited theatrical distribution. A high proportion are genre films (horror, science fiction, romantic comedy, etc.). For reviews, see B-Movie Central. Synonymous with B-grade and low-budget movie.