If I search for a phrase (e.g. alarm permit), will the results only show exact matches?

No.  By default, the search results will show matches for any word within the phrase.  In this example, you would receive results for all web pages and documents that contained either the word alarm or the word permit or both.

In order to search on an exact phrase, enclose your search phrase in quotations.  The search results for "alarm permit" will show matches for that exact phrase.