It describes a version of a universal library, containing books with every possible combination of 410 pages of letters, thus containing every book that ever has been and every book that ever could be written, drowned out by an immense quantity of nonsense.
Ok, that's how it supposed to work:
The library is divided into hexagonal chambers, each with 4 walls of bookcases, five shelves per wall, and 32 volumes per shelf with 410 pages.
So every one of those pages has random letters that could produce words So with nearly infinite variations, there could be every book ever written or will be written in there.
But really? Some say the search function just makes a page which inserted the searched words somewhere in the middle of the gibberish.
You can search manually and could find books in there but clearly, no one found anything substantial.
And look at it this way: Every book ever written or will be written would be tremendous, but this wouldn't even be the tip of the iceberg. Every VARIATION of the book would also be there.
Let's take a Novel with 100.000 words. Not only would there be a variation of the book with a different word randomly spread in there, no there would be a variation with a different letter!
If we size down a book to a lone sentence it would be this:
This is a text.
every possible combination of this would exist, like:
This is be text
This be is text
Bla bla bla text.
Now think of every variation with a different letter.
Surely, this is not possible.