Previously sliced and diced into varying increments and doled out between Gmail and other Google services, the search giant has simplified things by melting its free storage offering into a single 15-gigabyte chunk to be used as you see fit.
[I]nstead of having 10 GB for Gmail and another 5 GB for Drive and Google+ Photos, you’ll now get 15 GB of unified storage for free to use as you like between Drive, Gmail, and Google+ Photos.
With this new combined storage space, you won’t have to worry about how much you’re storing and where. For example, maybe you’re a heavy Gmail user but light on photos, or perhaps you were bumping up against your Drive storage limit but were only using 2 GB in Gmail. Now it doesn’t matter, because you can use your storage the way you want.
You can check your current storage here and purchase more if you need it. You may not see the 15-gigabyte clump right away: Google says the changes “will roll out over the next couple of weeks.”