ArcSDE is a *component* of ArcGIS Server (no longer sold separately). This component
still requires install before it can be used. Note that with ArcSDE there are *three* kinds
of install: Software on the server, database configuration, and software on the client.
The client component is covered by all ArcGIS products, so you just need to install the
server component (install) and database component (post-install).
You probably want to reconsider the "no links" directive, since the documentation is the
clearest information you will find on this topic.
- V