<p>When you are somewhere between version 1 and version 2, what do you do to maintain your software?</p>

<p>The terms Patch, Hotfix, Maintenance Release, Service Pack, and others are all blurry from my point of view, with different definitions depending on who you talk to.</p>

<p>What do you call your incremental maintenance efforts between releases?</p>

When I hear those terms this is what comes to mind:
Patch - Publicly released update to
fix a known bug/issue
Hotfix - update to fix a very
specific issue, not always publicly
released
Maintenance Release - Incremental
update between service packs or
software versions to fix multiple
outstanding issues
Service Pack - Large Update that
fixes many outstanding issues,
normally includes all Patches,
Hotfixes, Maintenance releases that
predate the service pack
That being said that isn't how we do updates at all.  We just increment the version and/or build number (which is based on the date) and just call it an "Update".  For most software I find that easier, you can easily see that one computer is running 1.1.50 vs 1.2.25 and know which is newer.