When viewing a record, you can check who last edited it via the Additional Info tab (you may need to reach this via the More tab).
Linked data (such as addresses, communication types, attributes and documents) do not update the last updated on within the main record, this information is found within each of the tabs using the Settings ; Configure Columns option and adding Updated On and Updated User detail.
This will state the last user who edited the record and the date/time it was edited.
There isn't a more granular log of each and every edit unless a particular table has auditing turned on.