When my COS code is executing in a Caché process it might want to interact with the host operating system. For the purpose of this post I'm focusing on a Windows host, but much of it applies to other host OS platforms as well.
A common example of host OS interaction is when my process wants to read from or write to a file. What credentials will apply when Windows is checking whether or not to allow me access to the file?
To answer that we need to consider another question. How did our process start?