While most of these storage types are viable, the most common one without a doubt is the cloud. Most apps have some sort of cloud storage, like social media platforms, more professional companies like Office 365 and Adobe, or even simple stuff like snapchat. This is because to send someone else a file, they must access it. Meaning that they can't access it if it's saved on your hard drive, consequently causing a need for cloud-based services to store files so that others can also see and access them. However, a lot of programs that include cloud-based storage, also provide a way to save files onto your hard drive or USB-stick/flashdrive. This is very useful, since having everything on the cloud isn't always the wisest option in the world, and even if you did put every single thing you saved into a single cloud, you'd most likely run out of space anyways.