Search result templates are very similar to Customizing Templates and define how the result of a search looks like.

The Basics, Web Document, Pre DML and Post DML sections are similar to content templates.

In 'DML for documents found' you give HTML/DML used for each single found document. For example, use

a result: <a href="#@ "/"+@webdbname+"/(ynDK_contentByKey)/"+key @#">#@ title @#</a><br>

to display one simple line per found document with a simple link in it.
You can use

[docNumber]

for displaying the number of each document.

Another good thing is to include nav-Parameters to the Link-URL, so that the proper category is expanded and activated in automatic navigators.
Luckily we can access any field of the found documents, and we just need the field 'category' for these nav parameters:

<a href="#@ "/"+@webdbname+"/(ynDK_contentByKey)/"+key+
"?Open&nav=expand:"+category+";active:"+category+"\\"+
key @#">#@ title @# (area: #@ category @#</a>

You can do even more with this technique: if you have customized subforms for using custom fields in different content document types (for example a 'News' may have some custom fields), you can even create different HTML for each found document depending on their type, so that a document of type 'News' is being displayed differently in the search result than standard content documents.
For that you only need to use @if statements in your DML formulas to ask for the 'subform' field or 'contenttype' field.