I'm glad you asked.
First off, congratulations. If you're reading this, you've been granted access to at least one metanode. This in turn means that you've either made a goodly amount of overall progress in your efforts to repair the server, or have made small amounts of progress in exactly the right places. Well done.
There are seven metanodes, each of which covers seven regular nodes scattered through the Labyrinth. To gain access to one, you will need to have provided the correct passwords for at least six of the seven associated regular nodes. To solve one, you will likely need all seven.
The passwords leading up to each metanode are closely related to a (in some cases arguably) well-known set of seven; each metanode uses a different set and a different relationship to that set. Some groupings may be obvious; others may not occur to you until you've solved the metanode puzzle. The passwords you gain from solving the metanodes themselves may be a bit longer than the regular node passwords; they can be phrases or even full sentences. Their purpose is to clue a specific order in which to arrange these answers for use in the meta-metanode.
For example, if seven of the passwords had been COLOSSUS, GARDENS, LIGHTHOUSE, MAUSOLEUM, PYRAMIDS, STATUE, and TEMPLE, there might have been a meta which yielded the answer "I WONDER WHERE THEY ARE ALPHABETICALLY", which would imply this ordering:
(The groupings aren't nearly as obvious in the actual Labyrinth, of course. There's usually a layer of obfuscation on top of the set members. To use the same example, we might have a set of words that can be found within the wonders rather than the wonders themselves, like THOU, DEN, TEMP, RAM, SOLE, TATU, and LOSS.)
But what to do once you have an ordering?
We're not telling. Heh heh heh....