which command difference

What is the difference between (unix-system �which [name]) and which [name] commands.

For example when I use the (unix-system �which visual_elite) command I get the following result:

/home/vhdl/edatools/mentor/visualelite/VisualElite-4.2.1/Linux2.4/bin/visual_elite

When I do the same on the command line using which visual_elite I get

enidl-atlas-schur <76> # which visual_elite
visual_elite is /home/vhdl/edatools/mentor/visualelite/VisualElite-4.2.1/visual_elite
Why do I have this difference?

Thanks,
Mihaela

This functionality can be the executable, like /bin/which, or a shell built-in, ksh calls it whence. If the PATH is not exported, the execuatble may get a different answer. Some are more chatty than others. The built-in is faster, but /bin/sh probably has neither which nor whence.