In the full-page detailed record view, you can view all data to do with a particular record on one screen.

The full-page detailed record view has three main parts:
Record details: All data under the record is visible.
Collaboration features: Comments, reminders, files, interactions, and history can be added and viewed.
Related Tables: Related Tables, if any, are displayed at the bottom of the page.
To access the full-page detailed record view, click on the View Record split icon at the left end of the record.

Check out this video to understand how to expand a record to a full-page detail view!