Most tracks in homes are made of plastic, commercial purchased, as plastic sections that are put together. Sectional track like this is very inexpensive and easy to work with. And with a little creativity, the layout of the track can be changed.
HOWEVER, every section meets the next section in a connection joint. Track manufacturers continually decreased the quality of the tracks, increasing the problems for the driver. The cars often get stuck or wreck when the come in contact with the connection joints.
The other problem with plastic tracks is trying to keep them completely flat. That means a piece of wood or a table. And other than small figure 8 tracks, most of us didn’t have the room to set up huge tables in our bedrooms. IMO, the less serious racers lost interest because of all the problems with the cheap plastic tracks.
Routed Tracks are usually made from wood, and have track grooves “routed” into the wood. After that, the guide/power strips are then installed making it a track without all the connection joints mentioned in the plastic tracks above. With this routed tracks though, a person needs a lot of dedicated room for placement of their track.