It would be easier to figure out the file extensions, like .doc is short for document, .txt for text, .exe for executable, etc..
For the series of letters and numbers it might not mean anything. Like a randomly generated password or game unlock code of sorts. Even the post office uses a sequence of 20 numbers for tracking packages.
The longer the numbers the more variation you can get. It's basically a complex set of variable arrays that a program or person can use to find a specific sequence within a possibly limitless set of variables.
Like say your game code is XRUP-8847-77IP-ULN9
That's about 36 possible combinations per digit. It doesn't really mean anything.