Cloud Computing is a term commonly heard these days, but what does it really mean? The term ‘Cloud Computing’ actually describes a broad range of services. The term ‘Cloud’ is generally used to classify software products and services that exist outside the common definition of traditional software (think Microsoft). The ‘Cloud’ is actually a stack of different services commonly referred to as Software as a Service (SaaS), Platform as a Service (PaaS) and Infrastructure as a Service (IaaS) that collectively make up the ‘Cloud’. Let’s take a closer look at each service:
SaaS – Software as a Service
SaaS is used to describe software applications designed for end users that are delivered over the internet in a “one to many” model. The software is provided ‘on-demand’ which means that end users can access the software when they need it. The provider may provide access to the software free of charge or through a pay-as-you-go model. The SaaS model allows end users to access commercial software that is managed from a central location without having to deal with upgrades and patches. The reduced management effort lowers cost of ownership and allows human capital to be allocated elsewhere.
Example: Google’s services such as GMail, Calendar, Maps and Drive are arguably the most widely known SaaS offerings.
PaaS – Platform as a Service
PaaS can be thought of as a computing platform that allows the creation of software applications quickly and easily without having to purchase and manage the underlying software and hardware infrastructure. PaaS simply refers to the delivery of a platform over the web for creating software. PaaS solutions typically provide integrated development, test and deployment environments, built in scalability, subscription management and integration capabilities based on industry standards.
Example: Force.com from Saleforce.com is a notable PaaS system that developers can use to develop multitenant applications hosted on Salesforce.com servers.
IaaS – Infrastructure as a Service
IaaS refers to the delivery of scalable cloud computing infrastructure including servers, storage, network and operating system software as an on-demand service. Customers who use IaaS buy access to infrastructure resources when needed instead of purchasing and managing all of the individual data center components. IaaS can actually be sub-divided into public cloud (shared resources accessed in a self-service manner over the internet) and private cloud (resources on a private network) but both refer to accessing infrastructure without actually managing it. IaaS is an excellent option for organizations with little capital for hardware, fast growing organizations and for those requiring temporary infrastructure.
Example: Amazon Web Services is one of the largest providers of internet based infrastructure services.
As you can see, Cloud Computing refers to multiple things: software applications, software development platforms and hardware infrastructure. The common element across these services is that they are delivered over the internet in a usage based model allowing an organization to focus on its core competencies rather than managing the underlying supporting technologies. Cloud Computing is a revolution within IT that will exist well into the future and an increasing number of SaaS, PaaS and IaaS offerings will continue to appear over coming years.