You have several elected representatives at different levels of government.
Your 3 Portswood councillors represent you on Southampton City Council. The Unitary Authority is responsible for all aspects of local services and policy, including planning, transport, roads (except trunk roads and motorways), public rights of way, education, social services and libraries. Most councillors are not paid a salary, but get a basic allowance for the work they do.
Your Southampton, Test MP represents you in the House of Commons. The House of Commons is responsible for making laws in the UK and for overall scrutiny of all aspects of government.