The first number is usually a letter. Typically E, L, T or X. E series are often not very sturdy. The other three are fine. L generally has slightly lower specs and lacks some features. T are thick with a bunch of ports and good specs. X are thinner and lighter. Z are high-end machines with AMD CPUs.
After that you have either a three digit number (e.g. 480) or something like '14 Gen 2'. The numbered ones usually have an extra memory card slot, while the Gen ones usually don't. Touchscreen is an option on most models, so you can't say that from the model number.