Many people use a "Google Account" regardless of their Android device. Some people use Gmail on a PC alone, while others say they want to use the convenience features of Google Maps on their iPhone. It is quite common to use the same Google account on multiple devices.
To find out which device / app your Google account is used for, log in to Google's website, open the "Security" tab, and click "Your device" and "Third-party apps that can access your account" Check the column. It lists the devices and apps that are signed in with your Google account, and you can force logout.
If you use an Android device, you can check the usage status of your Google account more easily. Open the screen in the order of "Settings" → "Google" → "Account service", select "All apps and devices" and select "Your device" and "Access account" displayed on Google website You ’ll see the same information as in the “Available third-party apps” field.
By tapping the displayed device / app name, you can check which service provided by Google is used and disconnect. If you disconnect, you will no longer be able to use your Google account on that app / device, which will prevent your computer or smartphone from being used without permission.