Board Thread:Game Discussion/@comment-84.198.97.58-20160415061702/@comment-27962837-20160415135136

For that another question: You need a G+ account for Google Play account - if you want a Play account, you have to make a G+ account, which you can use for a Google Play account. (Not sure if this is the best way to say this :D)

So. G+ account is a big thing. And it is used in Google Play (along with other places). So Play uses your G+ account. (Hope it's a better explanation now)