How is exchange volume calculated?

Could you please explain in detail how the exchange volume is calculated? I'm curious about the specific methodology and metrics used to determine the total amount of transactions that occur on a cryptocurrency exchange platform. I'm particularly interested in understanding if it includes only the completed trades or if it also takes into account pending or canceled orders. Additionally, I'd like to know if the exchange volume is calculated on a daily, weekly, or monthly basis, and if there are any other factors that could potentially affect its calculation.