Multiple products can be linked to a particular Category based on their attributes such as “Apparels” “Electronics” etc.
By creating a category, you no longer need to define Tax for each product, instead you can define Tax for a category and same will be automatically applied on all the Products in that category.
(Note : In case you have defined 12.5 % Tax for “Product A” which is linked to Category “Apparels” whose Tax is 5% . Then while creating Invoice , the Tax applied on Product i.e 12.5% will be given first priority)
You can check which is the Top Selling Categories in Dashboard