Can somebody please tell me the difference between 'date created' and 'date added'? Also, between 'arrange by' and 'sort by'? Thank you.

Date created was the date the file was created in the file system.

Date Added is the date the file was added to a particular folder. A bit more esoteric, Date Added is metadata, not file system data. Date created is essentially part of the file. Date added is a bit of extra data attached to the file.

Sorting orders Finder items by some criteria, like Date Created, Name, Size.

Arranging groups Finder items by some criteria. When Arranged by Date, it groups the items by a date range such as Today, Yesterday, Past Week, Month, Year, etc.

Within each arrangement, you can sort the items by some other criteria.

I select the 'Date Added' column to use as the sort order for 'Downloads' folders. This means that the files are listed in the order they were downloaded. I find it very useful in this context (and no other...).

C.

File systen data is created and managed by the file system automatically.

Metadata is created by the program that creates the file or by the Finder. It is done somewhat automatically, but it is not as robust as file system data creation.