How to Diagnose Heart Artery Blockage/ Coronary Artery Disease?

What does blockage of heart arteries or coronary artery disease mean?
How can I find out if my heart arteries are blocked?
Which is better at diagnosing coronary artery disease- stress tests or coronary angiogram?
Isn’t coronary angiogram a gold standard?
If coronary angiogram has all these shortcomings and is invasive, why do it?
If I have a normal stress test today, does that mean that I can be rest assured that I will not have heart attack next 5, 10 or 15 years?
What is the importance of tests for diagnosis of coronary artery disease?
What are different types of tests used to diagnose coronary artery disease or blockage of heart arteries?