A question on context

[white camellia]

How do you understand the first sentence in the following passage, especially the phrase "discourse microcosm"?


Context is a discourse microcosm formed by the grouping of words and expressions. Pragmatics studies the use of language in communicational contexts, focusing particularly on the relationship between sentences and the situations in which they are used. This makes context the first essential concern of pragmatics. Language, context, and culture are inevitably intertwined. Context is the experiential domain in which a given text makes sense in a culture. To engage a receiver or an audience and to successfully communicate a message, a discourse has to be linked to a particular context, which could be either sociocultural (colloquial exchange among friends, address to an authority figure, etc.) or professional (legal, medical, education, etc.). Each different context carries a different set of communicational expectations. Pragmatics examines language during such social interaction, investigating the meaning within the context, beyond the language’s grammatical structures.

[Virgil]

I take the first sentence as the thesis sentence of the paragraph, of which the rest of the paragraph explains the thesis. The first sentence uses the term "discourse microcosm," an an obscure term. The rest of the paragraph is a defining of this term with some specificity. At least that's how I read the paragraph.

[white camellia]

Thank you, Virgil. That's very clear about the structure.