เสียงที่ใช้ร่วมกัน

How you group your data changes what you see. Day-by-day records are too granular to reveal the big picture. Roll them up by month or year, and patterns like "sales peak in summer" start to appear. But once you've summarized data, you lose the ability to drill down. That's why you should always keep your original raw data safe and untouched.