Housing in Russia is very different than that in the west. Nearly all Russian people live in an apartment. The apartments are in large buildings usually from 10 to 15 stories high. The buildings are constructed of concrete and date from the 30's to the 80's primarily. Because housing is in short supply it is not uncommon for 3 generations to share an apartment, or even a couple of married siblings and their parents.
Russian families tend to be small, one or perhaps two children.
Moscow has central hot water and heat. This means that you have a device for controlling the temperature in your apartment called a window. In the summer the hot water plants may be shut down for maintenance for up to a month. All this aside, one of our favorite ways to stay in Russia, if staying for more than a few days in a single city, is to stay in an apartment rather than a hotel. The apartments are more roomy, less expensive, and it is kind of nice to be able to stock the fridge, and make a cup of tea in the kitchen when you want to.