If you learned C/AL in the Dynamics NAV era, the good news is that most of your knowledge still applies. AL , the language of Microsoft Dynamics 365 Business Central, kept the core concepts — tables, pages, codeunits, triggers but modernized the syntax and moved everything to an extension-based model. C/AL and the classic C/SIDE environment were retired back in Business Central version 15 (2019), and as of 2026 we are already 13 major versions into the fully AL-based world. This cheat sheet maps the most common C/AL patterns to their AL equivalents so you can migrate old code (or old skills) quickly. 1. The big picture: what changed Concept C/AL (NAV) AL (Business Central) Development tool C/SIDE (Object Designer) Visual Studio Code + AL Language extension Customization model Modify base objects directly Extensions only never modify the base app Object files Stored in the database Plain-text .al files in a project, version-controlled with Git Deployment Import .fob / .txt ...