The cloud is a concept that encompasses many technologies. Managing all of the tech and server infrastructure can be quite complicated. Cloud computing enables just renting of all the tech required to run your systems without actually having to manage any of it. It is changing how IT manages devices and even how applications are designed. SaaS (Software as a Service), IaaS (Infrastructure as a Service), PaaS (Platform as a Service) are all part of the cloud computing environment.
There is an unprecedented level of access today, to practically any type of software, any amount of compute resources and number of programming tools, that was not possible financially or logistically before the advent of cloud technologies.
Cloud computing can cut capital expenditures and reduce operating expenses when used efficiently. Instead of having to worry about managing all of the hardware and software, you can just focus on running your business.