Cloud computing, often referred to as "the cloud", is the availability of hardware, software and data via a network, often the internet, on request. The cloud largely replaces the hardware and software that someone uses on his computer. There are various types of cloud services like Software as a Service (SaaS), Infrastructure as a Service (IaaS), Platform as a Service (PaaS), public cloud, private cloud, hybrid cloud and more. Top benefits of cloud computing for organizations are costs, speed, scale, productivity, performance and reliability. Today's practical applications of the cloud can be found in data storage, e-mail, virtual offices, virtual collaboration, mobile apps and more.