An object that wraps a row in a database table or view, encapsulates the database access, and adds domain logic on that data.| martinfowler.com
The Web API is an RPC-style collection of methods that either yield information about Slack workspaces or allows your app to enact change within them. Learn how to formulate requests it will understand.| Slack API
The details on how tables and indexes work. Rows, pages, the heap and indexes are all covered, both on-disk layout and querying.| calpaterson.com
Active Record BasicsThis guide is an introduction to Active Record.After reading this guide, you will know: How Active Record fits into the Model-View-Controller (MVC) paradigm. What Object Relational Mapping and Active Record patterns are and how they are used in Rails. How to use Active Record models to manipulate data stored in a relational database. Active Record schema naming conventions. The concepts of database migrations, validations, callbacks, and associations.| Ruby on Rails Guides