Is there any difference on workflow features / functions in MOSS 2007 between SPS and STS Site Definitions? Example:
If I use SPS -> do i have same workflow functionality as STS site definition.
Maybe this is silly question but couldn`t find suitable answer...
The SPS and STS templates you refer to are not site templates, they are Site Definitions. There is difference between the SPS and STS definition of course. The main one being that STS basically replaces the SPS template, microsoft has classified the SPS site template as obsolete (remnand from SharePpoint portal server (SPS) 2003, even though other site defs seem to refer to and use the templates belonging to the SPS site def.
Both don't use workflows for any of the out of the box functionality provided by the def. and the templates referenced in them (not 100% sure about this though). You can of course add workflows to them once the site based on either def. has been created. You can even enable the publishing feature later on if need be, and then use the workflow used by sharepoint publishing for scheduling content publication. the mentioned defs. are for team sites and are pretty basic.
See this and this post for more on the SPS definition template.