To truly understand what discourse analysis is, it is important to first understand what discourse is. There are three ways in which we can describe discourse; each of which are of equal importance:
Firstly, discourse can be described as language beyond the level of the sentence. By this we mean that it is a type of language that extends past features such as sounds (phonetics), structures (syntax) and the parts that make up words (morphology).
The second description of discourse concerns language behaviors linked to a social practice; this suggests that a discourse is a type of language. For example, the most popular discourse you may have heard of is the discourse of law, whereby legal documents are written in as much depth as possible to avoid any vagueness and ambiguity. This style of writing is unique to the legal profession, meaning it is a specific kind of discourse.
Finally, discourse is described as being a system of thought. This is by far the most scientific description of the three, as it disagrees with the notion that knowledge and truth are either universal or objective. Conversely, it suggests that the ideas about knowledge and truth emerge from particular social and historical situations. An example would be the process of contemporary science and its attempts to produce objective knowledge. The concept of objectivity is itself socially constructed; it's subjective. This means that 'natural' categories are actually produced by human categorization, such as the differences between humans and animals; all humans are animals, but not all animals are humans. However, this is purely because humans have decided it has to be like this. Discourses appear to produce 'natural' knowledge, but they're actually shaped by powerful institutions (such as capitalism and heterosexuality).
This may all seem a little bit confusing at the moment, so for now just be aware that discourse, in its broadest definition, refers to a written or