Some unsatisfactory definitions

• “Too big for Excel”
• “Too big for a single SQL Server instance”
• “Data sets that are so large or complex that traditional data processing applications are inadequate.”
• “Velocity, volume, variety”
• “The convergence of enterprise and consumer IT”
• “The new tools helping us find relevant data and analyze its implications.”
• “A new attitude … that combining data from multiple sources could lead to better decisions.”

My definition (today)

Digital traces of everyday activity, collected and stored at much finer resolution and higher frequency than pre 2000

• wearable devices like fitbits
• individual financial transactions
• mouse events
• motion sensors
• CCTV
• GPS tracking in phones and cars
• smart electricity meters

Different types

The data revolution

• New statistical methods post 1970
• Rise in computing power
• Increasing scope of data capture
• AI explosion post-2000