Class is useful for tracking performance of individual segments or divisions of your business.
Illustration: ABC Co. manufactures Pistons used in auto mobiles. They sell it to Car manufacturers as well as to two wheeler manufacturers and wish to track sales made to car manufacturers and two wheeler manufacturers separately. Then they can create Car and Two wheelers as two classes and tag the class in invoice, sales order etc.
For using the class, class tracking has to be enabled in the Setup. To enable Class tracking Go To Setup > Apps > Packaging > Installed Packages > click Configure in Arka Inventory > Go to General section > Turn on Track Class
To create a new Class, in the main page Go to More > Class > New.