champagne / champaign are similar-sounding terms with different meanings (referred to as homophones). To better understand the differences, see below for definitions, pronunciation guides, and example sentences using each term. 👇
champagne: (noun) a white sparkling wine either produced in Champagne or resembling that produced there. (noun) a region of northeastern France.
champaign: (noun) a university town in east central Illinois adjoining Urbana.
champagne: sh·ae·m·p·EY·n
champaign: ch·ae·m·p·EY·n
(Examples are Wikipedia snippets under the CC ShareAlike 3.0 license. Definitions drawn from WordNet.)