Genre is a type of music, film and anything which can be performed in different ways throughout media. There are differences and similarities, predictable or expected. It should also be unpredictable. Different people see genre in different ways- people who consume it.

‘saddled with conventions and stereotypes, formulas and
clichés and all of these limitations were codified in specific genres.‘

The work of Steve Neale is often referred to when discussing genre. One area he looks at, is the relationship between genre and audiences. For example, the idea of genre as an enabling mechanism to attract audiences based around predictable expectations. He argues that definitions and formations of genres are developed by media organisations (he specifically discusses the film industry), which are then reinforced through various agencies and platforms, such as the press, marketing, advertising companies, which amplify generic characteristics and thereby set-up generic expectations.

In general, the function of genre is to make films comprehensible and more or less familiar.

meanings

repertoire of elements,  corpus, realism 

key elements-consistently repeated, collection of written texts,  a way of portraying or thinking about reality.