why is my ipnone contacts appearing on my mac

You can turn OFF contacts ON YOUR MAC to prevent synching with your iPhone by doing the following-

On your Mac, Open System Preferences ➔ Apple ID (Top Right) ➔ iCloud (Left Column) ➔ Contacts - UNCHECK Contacts. This will prevent synching of contacts with your iPhone.

Axel F.

There are several articles from a variety of sources online, including Apple Support.

• Set up and use iCloud Contacts - Apple Support

https://support.apple.com/en-us/HT205754

As the following is not an Apple article, you may find others too; stating similar.

This one tells Cloud basics: "What is iCloud and How Do You Sync it to an iPhone"

and how to toggle functions 'Off or On' in iPhone settings. (from dummies.com)

Good luck & happy trails!☀️🙈

1. Because your iPhone and your Mac are signed on to the same Apple ID
2. Because you are using iCloud to synch your contacts across your devices (iPhone and Mac)

Axel F.