Chrome on Mac (and almost on all other devices) tracks some information like your web searches, location, the sessions etc. Some web apps use this info to serve you better, contextually.
You can, of course, turn this off through the “Do Not Track” feature. By default, Do Not Track is turned off (which means Chrome will track your search and other information). When enabled, Chrome respects your privacy and doesn't let any web app to track your activity in the browser.
Here is How to Enable “Do Not Track” in Chrome on the Mac:
Step 1: Open Chrome on your Mac.
Step 2: On the upper menu bar, you will see the Chrome Menu. Click on it and afterwards select “Settings.” Alternatively, you can also type chrome: //settings/ in the address bar (omnibar).
Step 3: Click on “Show Advanced settings.”
Step 4: Beneath the privacy header, there will be an option, “Send a ‘Do Not Track' request with your browsing traffic.” Check the box in front of it to enable the option
Step 5: A confirmation message will show up. Click on “OK” and you are done!
Enabling/disabling the tracking feature has varied effects depending on the websites you visit/use. If, you use websites that function as web apps or as services that store local data on your browser, you might have to disable the Do Not Track feature.
This is also true in the case of websites that need your location information to work properly. For instance, there are websites/web apps that tell you about the weather in your locality. They track your location through your browser to fetch the weather info. If you enable Do Not Track, the web app might not be able to function at all.
In most cases, websites tracking data from your browser have only limited access. Still, if you'd rather have more privacy, you should enable the Do Not Track feature.