From the Microsoft Dynamics CRM Blogs: CRM Vocabulary; Customer Care Accelerator; Outlook CRM Client and Email Router Deployment; Free Utility to Bulk-Delete CRM Entity Attributes
Building your CRM Vocabulary: "Customizing" and "Extending": From Richard Knudson's CRM Trick Bag:
"In Dynamics CRM lingo, the word "customizing" is conventionally used to refer to "schema" customizations: customizations to forms and views, entities and attributes, relationships, and the like. These are "schema" customizations since the changes you make are actual changes to the database schema, and are stored as metadata in the SQL database. These are, for the most part, no-code customizations, and the amazing mileage you can get out of them is a big reason for Dynamics CRM's exploding popularity as a customization platform."