Software Testing Types (A Common Question with Different Answers)

Hi Reader,
I wrote Common Question as this is one of the Most question asked in any of the Interview Question by Testers.but the Answer of this Question is not So Simple....:)
Its very Difficult to categorize the Testing types because each Type of testing is related to other in a very complex way...:)

When I Started my Career in S/w Testing Everytime When i Was the Same question I had Different Answers(Reason being Types of Testing are not limited and there is no Defined Hierarchy for them)

Question 1- Can we Categorize Types of Testing....?
Answer 1- Yes,We can.

Question 2- How can we Categorize Types of Testing...?
Answer 2-Before Categorizing . Let us Recall what we do in Testing.
                  We Find defects in Software    (Correct)
So We can Categorize Defects according to User Requirements and Expectations.

For Example -Functional Defect if The System is not functioning according to User expectations.
                         Usability Defect- If the System is not Usable.
                         Security Defect-If the System is not Secure.
                         Performance Defect- If the System is not performing Well.

Now To find the above defects we should have Skill Set as well we need to perform and execute different Test Cases.
So to do all this we need to categorize our Testing Process.

So there Can be many ways in which Software Testing can be Categorized:-

Based on Knowledge of System
1-Black Box Testing
2-White Box Testing
3-Gray Box Testing

Based on SDLC we categorize in following manner
1-Unit Testing
2-Integration Testing
3-System Testing
4-User Acceptance Testing (UAT)

Based on Experience we Can Categorize
1.Functional Testing (Installation,Regression,Compatibility,Accessibility)

2.Non Functional Testing (Performance,Load,Stress,Usability,Stress)