ZopeTerms

IMHO, Zope Terminology is the most confusing aspect of the system. There are lots of concepts that have different names than you are probably use to. I believe most of these will be addressed by the Zope Book published by O'Reilly.

ThroughTheWeb? - (aka TTW) the interface interface of ZOPE. being able to construct objects through a web browser. This is something the ZOPE community boasts about and uses this acronym quite a bit.
ZSQLMethod? - methods invoked that return SQL results
Python Script (aka PythonMethods?, TTW Python, etc) - free standing python code that is used to seperate logic from content.
Acquisition - dynamic inherientence (the URL traversal determines inheritence)
External Methods - Python code located on the disk, that is not maintained/edited through the web and is not confined by ZOPE's security model to obey the same laws as TTW scripts/code.
DTML Method - kinda like a template, basically the base ZOPE object that allows dtml to be rendered. takes the namespace from its container.
DTML Document - used for content (primarily), dtml can be used. its namespace is not inheriented from its container. (although acquisition does still apply)
Namespace - this is the root python concept of where variables live. namespace in ZOPE (as manipulated by DTML) can be somewhat hairy. but only takes a few examples to go through (ZBook?) before you get the jiest.
Versions - ZOPE's versions have some limitation, but are continually claimed to be used as long running transactions to content. versions have some warts (ZSQLMethods? and ZCatalog? has some oddities w/ versions)
Mountable Storage - allows for a flexible data store underneath a ZOPE branch structure.
ZODB - Transactional Distributable Object Database that is the core of ZOPE. Has multiple Storage implementations, where it can store the underlying structure - Filesystem, BerkeleyDB?, Remote (on a another server), Oracle, and more.
Transactional Undo - a Undoable Undo