What is the formula for trading volume?

Excuse me, could you please clarify what the formula for trading volume is? I understand that trading volume refers to the total number of shares or contracts traded within a specific period of time, but I'm unsure of the mathematical equation used to calculate it. Is it simply the sum of all transactions made during that period? Or is there a more complex formula that takes into account factors such as the price of each trade and the total number of buyers and sellers involved? I'd greatly appreciate it if you could provide a clear and concise explanation of the formula for trading volume.