Suburb and Downtown

Suburb

The word suburb refers to a smaller residential neighborhood outside of a city.
Ex: My neighbourhood is a suburb of Birmingham. It takes me about an hour to get into town from my house.
Ex: I would rather live in a suburb than be in a bustling city. The noise and pollution get under my skin.
The common phrase the suburbs refers to a group of areas or neighborhoods outside of the city. It implies that middle class families live there.
Ex: As a child, I dreamed of living in the suburbs. I still value family life, but I live in an apartment in the city until I marry and have children.
Ex: I think most people think about owning a home in the suburbs and commuting to the city for work. It is a worthwhile goal.

Downtown

The word downtown refers to the main commercial area of a city. In British English it can be the central or lower part of a city and it is called city centre or town centre.
Ex: My office is downtown. The traffic gets under my skin, but it is best to work where most of the business is done.
Ex: Are you going shopping downtown or closer to home? I prefer to go into the city where all of the action is!
The word downtown can also be used as an adjective, mainly in American English, to describe the central part of a city.
Ex: Some people love downtown New York City. I prefer to be on the outskirts of the city where there are not so many people.
Ex: During my travels in Europe I found downtown Munich the most interesting. I appreciated the fine restaurants and historical buildings.