Hi @LiquidSnake Linked contacts are basically a merge when one or more contacts contacts are in essence the same , they will be linked under one contact profile. Therefore should result in more efficiency if for instance you have several contacts in different apps. See some information here https://mobilepains.com/what-does-it-mean-when-a-contact-is-linked/#:~:text=Linked%20contacts%20are%...
You must keyboard permissions for contacts and take it the prompt appeared asking if you wanted it sorted this way.
If at a later date you wished to unlink should be relatively straight forward.
I do not work for Samsung or make Samsung Products but provide independent advice and valuable contributions.
My Device- S21 Ultra 5G ( SM-998B/DS ) CSC= BTU , 12GB/256GBOne Ui 5.1,Android 13 .