Software as a Service (SaaS)
It´s a distribution model in which an IT company provides software support and maintenance to it´s customer.
A customer can access his company´s information from anywhere in the world at any time as well as remote application access.
SaaS does not require patching from final users since it works with centralized upgrades.
An SaaS customer does not require a specialized area fot it´s system support.
IT providers guarantee the customer´s applications correct functionality and availability at any time.
SaaS does not require a customer to buy a software license, a customer will just need to pay for software usage. Customers can also choose their own OS.
Platform as a Service(PaaS)
PaaS takes over the complete applications development and implementation cycle from the web. PaaS is abele to get applications to work in one single process.
PaaS also ensures system scalability so the developer can manage as many users when they need their applications and keeping system security at the same time. Sharing source code between several developers spreaded worldwide improves the developers team work.
A PaaS provider will take care of all the basic software requirements so developers start innovating in no time.
As a result of all this, customers do not require new hardware or software since putting an application online takes no effort at all once the development process completed.
Infrastructure as a Service(IaaS)
This model allows customers resource scalability.Anytime components are about to be scaled up or down the service keeps the same.
IaaS is the new and powerful way to work with servers. Servers can be used simultaneously by more than one OS. Remote datacenters are administrated by programs. This allows the control of numerous processes.
Customers pay only for the resources they need.
By using several datacenters online service is always available.