As all have stated, the rail is pretty much the same etc. etc.
What is different, however, is the sleeper size/style. There are two basic slepper/tie types, one called Euro, and the other American (for want of a name). The Euro style is basically for LGB track, or copies thereof.
The American style is one of the versions of Aristocraft track. it has smaller, and more sleepers/ties than LGB Euro track. It looks better with trains scaled at 1:29. It does look wrong with LGB, Bachmann, etc etc., but, it is still 45 mm gauge, and any brand will run on any 45 mm track, subject to the curve radius you choose. Basically, the longer the wheel base of your stock, the bigger the curve radius needs to be. Many proponents of this hobby will tell you to use the largest radius possible, a noble suggestion, but, just starting out, R1 is both plentyful, and cheap(ish). I've used R1 for 18 years now (check out my thread on Taita Gorge Railway).
The 'classic' train set track is what is called R1 (radius 1), and is 2 foot radius. Most LGB will get around this, as will most small to small medium stock.