While many homes do not have an Internet connection, it is becoming more and more common. Wireless connections are easier and cheaper to add for home use.
Ways to get Internet connections vary in different parts of the world. In some places the connection is purchased through the telephone company, in others it is bundled with other media, like TV shows delivered through a cable or satellite dish. (I think in some companies connectivity is sold via the post office?)
Sometimes an apartment complex provides internet connectivity as part of the rental.