iPhone 7 and iPhone 7 Plus come in three capacities: 32GB, 128GB and 256GB. Jet Black and iPhone 7 (PRODUCT)RED™ Special Edition come in 128GB and 256GB capacities. GB stands for gigabytes. The more gigabytes you have, the more content you can store on your iPhone, such as apps, games, photos, HD videos, music and movies. If you have a large music or photo library, or lots of apps, it’s a good idea to consider an iPhone with a larger capacity. If you rarely download apps or you don’t take many photos or videos, an iPhone with a smaller capacity may be better for you.