This is a plastic road and rail set. There are various starter sets, varying in price, ours cost around £40 for enough track to make an oval about 4'x 3' and a road, about 2' x 2'. with a tunnel. You can buy individual pieces of track [£3-5] accessories such as stations.
The trains are around £10.99 and include an engine and 2 coaches or trucks. We have [amongs others] a Eurostar, a Virgin Train, Thomas, Percy & Henry. They are all battery powered [some take C some AA}]. We have a few cars and Bertie the us for the road, but in our house it is rarely used and mostly they just have the rails out.
Our set has been in daily use for over a year now, but Harry [3 1/2] has only recently managed to fasten the trains together without my assistance. Only one piece of track [a long hill piece] has had to be replaced through breakage. So I think it has been very good value.