You can search for text or tags on a single wiki or on multiple wikis. Searching across multiple wikis lists only pages that you have access to.
Text searching lists pages with the following types of matches:
Most recent author
You can use advanced search features, such as quoting text, to get exact matches.
For example, if you search for "anne johnson" without quotes, you'll find pages that include "anne" and "johnson" but not necessarily together. You might find pages with "Anne Smith" and "Mike Johnson." However, this is useful if you search for "anne plan" and find all pages with both "anne" and "plan." If you use "anne johnson" (in quotes) you'll find pages without text between "anne" and "johnson."
Usually, you tag a page when that page is about a specific subject. For example, if you have a page about planning that Anne works on, you'd tag it with "plan" and "anne." When you search for the "anne" tag, you'll find pages that specifically involve Anne, but not pages that just happen to mention her.
You can search for a combination of tags, like "anne" and "plan," which would show pages that use both tags. This is an improvement over doing a text search for "anne plan" because you won't find pages that just happen to mention "anne" and "plan."
You can also combine a text search and tags. For example, let's say Sunil doesn't tag pages related to himself with "sunil" but he wants to find pages related to himself that also deal with Anne and planning. He could do a text search for "sunil" and then refine the results using the "anne" and "plan" tags.
After you find the pages you're looking for, you can save your search criteria as a smart filter for future use. You can search on the smart filter, which can include text and tags, and then apply more tags to further filter the search results.