IaaS: Infrastructure-as-a-Service
The first major layer is Infrastructure-as-a-Service, or IaaS. (Sometimes it’s called Hardware-as-a-Service.) Several years back, if you wanted to run business applications in your office and control your company website, you would buy servers and other pricy hardware in order to control local applications and make your business run smoothly.
But now, with IaaS, you can outsource your hardware needs to someone else. IaaS companies provide off-site server, storage, and networking hardware, which you rent and access over the Internet. Freed from maintenance costs and wasted office space, companies can run their applications on this hardware and access it anytime.
Some of the biggest names in IaaS include Amazon, Microsoft, VMWare, Rackspace and Red Hat. While these companies have different specialties – some, like Amazon and Microsoft, want to offer you more than just IaaS — they are connected by a desire to sell you raw computing power and to host your website.
PaaS: Platform-as-a-Service
The second major layer of the cloud is known as Platform-as-a-Service, or PaaS, which is sometimes called middleware. The underlying idea of this category is that all of your company’s development can happen at this layer, saving you time and resources.
PaaS companies offer up a wide variety of solutions for developing and deploying applications over the Internet, such as virtualized servers and operating systems. This saves you money on hardware and also makes collaboration easier for a scattered workforce. Web application management, application design, app hosting, storage, security, and app development collaboration tools all fall into this category.
Some of the biggest PaaS providers today are Google App Engine, Microsoft Azure, Saleforce’s Force.com, the Salesforce-owned Heroku, and Engine Yard. A few recent PaaS startups we’ve written about that look somewhat intriguing include AppFog, Mendix and Standing Cloud.
SaaS: Software-as-a-Service
The third and final layer of the cloud is Software-as-a-Service, or SaaS. This layer is the one you’re most likely to interact with in your everyday life, and it is almost always accessible through a web browser. Any application hosted on a remote server that can be accessed over the Internet is considered a SaaS.
Services that you consume completely from the web like Netflix, MOG, Google Apps, Box.net, Dropbox and Apple’s new iCloud fall into this category. Regardless if these web services are used for business, pleasure or both, they’re all technically part of the cloud.
Some common SaaS applications used for business include Citrix’s GoToMeeting, Cisco’s WebEx, Salesforce’s CRM, ADP, Workday and SuccessFactors.
Source:
