AL is the programming language that is used for manipulating data (such as retrieving, inserting, and modifying records) in a Dynamics 365 Business Central database, and controlling the execution of the various application objects, such as pages, reports, or code units. This session will accelerate your skills in understanding how to Personalize vs. Design vs. Develop in the environment and see the difference between Per-Tenant Extensions and AppSource Extensions.
To adjust the volume hover the cursor over the volume bar 
