"Heteroglossia" literally means "other voices" or "different voices." Bakhtin believed that the complexity and diversity of many different voices was overlooked in literary and sociological studies. Bakhtin thought that the novel was the best literary form to depict and analyze heteroglossia. For example, in a poem there tends to be one voice (longer poems and epic poems being notable exceptions). Also, with poetry, the language is often stylized and limited in form and style. But in a novel, there is more opportunity to have many different voices, from different backgrounds, cultures, and social positions. Bakhtin was very interested in the many voices and differences in the novel's characters: the "different voices" or heteroglossia.
Therefore, Bakhtin thought that the novel was also a good form for establishing the diversity of voices in any particular moment of history:
The novel orchestrates all its themes, the totality of the world of objects and ideas depicted and expressed in it, by means of the social diversity of speech types [raznorecie] and by the differing individual voices that flourish under such conditions.
Bakhtin thought that this, heteroglossia, was the "basic distinguishing feature of the stylistics of the novel."
Bakhtin also wrote about the dialogism in novels. Meaning two (or more) words (dia - two, logos - word), the words of each voice refer to other aspects. In a way, this means that each character, by using language and references to things particular to his/her culture and socio-economic background, is having an indirect dialogue with himself. For example, when a character refers to his difficult labor job and his economic struggles, these words and ideas refer to other elements. Thus, these ideas refer to (as if in conversation with) other ideas and words. So, the novel is made up of many voices (heteroglossia), each of which establishes ideas and a persona by referring to (being in dialogue with) other ideas. (This concept of referring to things beyond the text was a precursor to "intertextuality.")
For Bakhtin, the novel illustrated the confluence of many voices, a literary depiction of the interaction of different social classes and characters. Also in the novel, the method of dialogism is illustrated as the interplay of heteroglossia reveals other aspects of character, theme, and interaction.