Confusion over identical named files but in Macintosh HD or iCloud

Using a MacBook Pro and Ventura 13.4.1., if I search for a folder, sometimes but not all of the time, the search on the computer results in getting two seemingly identical folders.

One folder is named iCloud Drive.....x.x.x. and the other named Macintosh HD...x.x.x.......

Why are there seemingly duplicates made in iCloud and on the HD? Why are not all the folders and files done this way?

How does one organize to know which folder or file to use next? Does changing one change the other?

Thank you for help in this very confusing issue.