There’s a very good chance that many of us have more than one Google account. There might be one we made a decade ago that we’ve been using up until now. Then there might be another one that you created because the old one was getting way too many spam emails. Then there might be one for your work or business, one for school, and so on.
Basically, it’s not uncommon to see people with multiple Google accounts. Now, if you’ve signed into all of them, one of them will be the “default” which is the main account you see whenever you open up Chrome, log into Gmail, on Android, and so on.
There is essentially no difference between your accounts, but if you care about syncing search history, YouTube preferences, and more, across multiple devices, then making sure all the default accounts are the same is important.
Now the process of changing your default Google account is simple and straightforward, but it is slightly troublesome because it means having to sign into all your accounts again. If you’ve enabled two-factor authentication across your Google accounts, then this process could take a while, but otherwise it’s a pretty simple process.
If you ever need to change the default account again, then just follow the steps above again. At the moment Google does not have an easier way to change default accounts, so until they do, this is what you’ll have to do.