Different sections of Detailed Lead view show various types of history.
At the top right corner of Detailed Lead view you can see Creation date, Last and Next action dates and the Source of the lead (if you hover over the i icon).
Under this block there are opportunities and sales statistics.
All the information regarding submitted forms, purchases, placed calls, sent emails, upcoming actions, etc. is stored in TIMELINE.
One more place in history is PROFILE. Here you can see visitors data from all the devices they use, locations they browse from and pages they visit.