I have no great and abiding interest in trains and yet I have somehow accumulated several postcards showing them. Many, but not all, are special trains for tourists rather than the average train taking commuters to work.
One, as you can see, is a vintage card showing the Royal Mail night mail train. At the bottom left is the only tram in this mix.
More to the point of postcard collecting are the cards which show specific places, known as topographical in specialist collecting circles. They are the sorts of cards generally sent home by tourists. The ones I show below are just a few of the many I have sent (to myself as well as to others) on my own travels.