History of time series
Before big data was popular news
Classical time series
Until recently, time series practitioners used mostly the classical approach, which provides the foundations for classical and modern data management, analysis and forecasting.
Challenges of scale, granularity and irregularity brought about by IOT and sensors
Machine learning for time series
Machine learning was not created for time series. A lot of work still to be done, but it is widely used.
Different open source software
Software
Some good for some things, other good for other things, but we need software to analyze data.