Suppose I want to find what information DMS has on a nitrogen laser. I could do a search on nitrogen or laser. Maybe I’d find many articles on fertilizer in the process, or the CO2 laser. I could search through the results, and hope that my desired results are near the top. Our set is small enough that my desired result ought to be in the search results, at least, and probably not too far down the list. But, this illustrates my point that search is not an appropriate indexing tool, even if Google got rich off it. It doesn’t actually find what you want efficiently, unless it gets lucky.
If I go into a library, I know to go to the section on lasers, instead of the section on cooking. That’s what the Dewey Decimal System is designed to facilitate.
I could create a page on my Nitrogen Laser Project, and just upload it to the wiki home page. Maybe I’d put some links on various other pages. This works if your wiki is small, but it’s like tossing your clothes on the floor. You can find what you need if the sample set is small, but it is disorganized and inefficient.