The Dover district is divided into two areas, known as parliamentary constituencies, each of which elects a Member of Parliament (or MP) to represent the people of their constituency in the House of Commons at Westminster.
These are the constituencies of Dover and Deal (which covers the majority of the Dover District) and Herne Bay and Sandwich (which covers some of the wards in the northern part of the Dover District).
You can find the details of your local MP on the website of the UK Parliament. This also includes a post code based search function if you are unsure as to which constituency you are in.