Difference:
Subject matter: the material that constitutes a literary work, that is, the life events or life phenomena described in the work. For example, the theme of Wang Jian's Rain in the Mountain Village is to describe the working life of farmers in the mountain village after the rain.
Genre: the expression of literary works. It can be classified according to various standards, such as poetry and prose, if there is rhyme or not; According to the structure, it can be divided into poetry, novel, prose, drama and so on. For example, the genre of Wang Jian's Rain in the Mountain Village is poetry, which is a seven-character quatrain in Tang poetry.