Before the Internet of Things (IoT) there was Cloud Computing. Cloud Computing is the centralization of services and storage that can be accessed anywhere in the world over the internet. Large companies such as Microsoft and Google (to name a few) embraced this vison and offer many Cloud services.
A good example is Microsoft Office. Originally you would have had to install MS Office on each machine that would be accessing the program. It was not a hardship for a home user with one machine but for a company with multiple systems, located throughout a building or across the globe, it was very time consuming and problematic. With Cloud Computing, MS Office is located on the cloud (on a Microsoft server) that can be accessed from anywhere over the internet. This allows companies to buy a subscription for each user and direct them to the correct site.
Data storage is another item that uses the convenience of the cloud. A user can store data (such as pictures) and then retrieve the data on any connected device anywhere in the world.
IoT is merely an extension of the cloud. With IoT not only are computing devices connected to the cloud but all types of devices (cars, refrigerators, coffee machines, etc.) and sensors are also connected.