Youtube Income Taxation & Expense Writeoff

Is YouTube considered as a Business? If yes can you claim expense write-off from it.

I read Section 2(13) of Income tax act which says Business is any activity of Trade, Manufacturing & Commerce. But I couldn't find what is considered as Trade, Commerce & Manufacturing.

If a person opens a dance classes, What will it be considered as Trade/ Commerce/ Manufacturing? Because as per dictionary definition it seems to me as none.