We're here to help you pick out the right scale to start your journey into the the World's Greatest Hobby, model railroading.
The most popular scale is HO (Half-O Gauge). This scale became popular after World War 2 when many servicemen returned home bringing back handmade model trains from Europe and Asia. The ratio of 1/87th the size of the prototype made the trains smaller than the much larger pre-war O Scale trains. This was important because post war housing was much smaller and lacked the room to display the larger O Scale trains. HO allowed the model railroaders of the time to build a train layout in this available smaller space. The prices was also much cheaper than O Scale, Keep in mind, when I mention O Scale I'm not talking about Lionel O Gauge Toy Trains.
During this same period, S Scale trains came on scene. These trains were 1/64th the size of the real trains they represented. They were an "In Between" size being in between O Scale and HO. There still is an active community supporting this scale but lately availability of merchandise has been on the wane.
N Scale (1/160th the size of the prototype) arrived from Europe in the early 1960s. At first the trains were of European prototypes but over the years more and more North American trains are available to N Scalers. If you are tight on space,this is the scale for you as you can build a model railroad empire in a small space.
During the early 1980s a German train manufacturer by the name of LGB (Lehmann Gross Bahn) introduced the world to large scale models. The size of these trains (1/24 proportion) was an instant hit. You could find these trains in back yards across the country as garden railways, melding gardening with model railroading.
Last but least in Z scale, the smallest of all model trains. It's tiny compared to HO scale and has an avid fan base for those looking for brag rights of having the smallest layout in a small suitcase.