Here is the question you are trying to solve while working on this case study:
Which borough of London has seen the greatest average increase in housing prices over the (approximately) two decades covered by the dataset?
A borough is just a fancy word for district. There are 32 London boroughs within Greater London, and each borough has its own governing council. As you can guess, some of them are more desirable to live in and will reflect that desirability in a greater rise in housing prices.
Data comes from the London Datastore: a free, open-source data-sharing portal for London-oriented datasets.