Test summary report gives us the complete status of Testing
stage  like as follows

No of test cases prepared and executed
No of defects Open,resolved and closed
Breakdown by severity and priority 
day wise testing information

It is the product outcome of the testing , this report
should summarize all of the testing that was performed
during testing phase.  This report can be produced once test
plan is completed, the tests like unit test, integration
test, system test, security test and user acceptance test
completed, and all associated test reports available.

  This report is evaluated by Test leads or test manager or
test inspection team.

    1. This report gives the status of the product tested
across various levels.

With the test summary report project management / customer
will be informed about

  1 The current application quality
  2 What are the areas covered under test

With this summary report project management / customer can
decide or estimate when the application will be ready for
public, decide if they require any correction / changes.
   
HOpe you might be clear with this