What's the difference between unix built-in `pwd` command and it's $PWD environment variable?

In other words, using $PWD is sufficient, because pwd might not give you better results (for any definition of better) anyway.

The difference between the /bin/pwd external command and the built-in is that the external command doesn't know what set of cd operations got you there and therefore doesn't pretend that your current directory is somewhere down a chain of symlinks; it gives you the direct path from root to your current directory, rather like the realpath() function would.

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.