Application language (AL) is the language used to create objects in Microsoft Dynamics 365 Business Central. With AL, you can manipulate data, and the statements and functions are able to read, write, and change data in the Business Central database. Use with the [dynamics-business-central] tag
AL is a programming language to create objects in Microsoft Dynamics 365 Business Central. From the Microsoft site
All functionality in Business Central is coded in objects. The extension model is object-based; you create new objects, and extend existing objects depending on what you want your extension to do. Table objects define the table schema that holds data, page objects represent the pages seen in the user interface and codeunits contain code for logical calculations and for the application behavior. These objects are stored as code, known as AL code, and are saved in files with the .al file extension. The AL Language extension also supports the multi-root functionality which allows you to work with multiple AL folders within one workspace.