title: How and when does ngen.exe work?
body: <p>I want to know the benefit of pre-JIT compilation (ngen.exe). What is the role of the <a href="https://en.wikipedia.org/wiki/Native_Image_Generator" rel="noreferrer">Native Image Generator</a> (NGen) process and why is it required?</p>
  
  <p>Please provide an example.</p>