According to Mijail Bakhtin, discursive genres are a series of language statements that are grouped together because they have certain similarities in their thematic content, their verbal style and their composition. 
Discursive genres can be understood as typical discursive forms that classify sentences according to their “relatively stable” characteristics, understanding the real unit of communication by sentence. The latter can be oral or written, they occur in different spheres of human praxis and reflect the socio-historical conditions and the purpose of each of these spheres through three elements: thematic content, style and composition. According to these characteristics and based on the complexity of the statements, there will then exist, according to Batintín's theory, two discursive genres:
1. Primary or simple.
2. Secondary or complex.
In his theory he says: “the same correlation between primary and secondary genres, and the process of their historical formation, shed light on the nature of the statement (and above all on the complex problem of the mutual relationship between language and ideology or world view) "
They are those that correspond to daily communication, oral or written. The conversations that take place in the different areas of daily life fall into this genre and are characterized by being simple, spontaneous and, in most cases, immediate responses to a conversation. The phrases are eloquent. Examples are everyday dialogues, letters, onomatopoeia, greetings, etc.
Secondary / Extreme Genres
These are much broader, complex and much more elaborate, they are born in conditions of the most complex cultural communication and are created from the primary genres, most of them are written and necessarily go through a planning process. Taking these characteristics into account, a political discourse, a scientific report, a poem, a chronicle, among others, are examples belonging to this classification.
Characteristics of discourse genres
Discursive genres can be classified and analyzed according to four parameters or characteristics:
The subject (what is he talking about).
The structure (how it is organized).
The style (what linguistic resources it uses). According to Bakhtin, the style would have to do with the lexical, phraseological and grammatical resources of the language.
Every statement can reflect the individuality of the speaker, because it belongs to him. But not all genres lend themselves to absorbing an individual style.
The function (what it is spoken for and for whom it is spoken).
The concept of gender
The concept of non-literary discursive “genres” dates back to the time of Aristotle, who on his part made a first classification of discourses:
a) Forensic or legal
b) Deliberative or political
c) Epidictic or occasion
These speeches correspond to the institutional setting and, necessarily, are possible through oratory. This criterion, in relation to the field in which these discursive genres are produced, will be key for future studies on genres.
Bajtín, Mijail, Aesthetics of verbal creation, Madrid, Twenty-first century editors, 1982Calsamiglia and Tuson, The things of saying, Barcelona, Editorial Ariel, 1998