What is the difference between private and public cloud?

Public Clouds

A public cloud is one in which the services and infrastructure are provided off-site over the Internet. These clouds offer the greatest level of efficiency in shared resources; however, they are also more vulnerable than private clouds.

Private Clouds

A private cloud is one in which the services and infrastructure are maintained on a private network. These clouds offer the greatest level of security and control, but they require the company to still purchase and maintain all the software and infrastructure, which reduces the cost savings.

Simply: Public cloud provides your own secure unit, external maintenance is handled like harddisk and RAM space. your work here is to just maintain the unit.

private cloud depends on the individual of what kind of infrastructure they need (ideal choice).. here you have security, scalability, cost advantages