Basic Cloud Terminology
Author: Stephen Brawn, Northwestern University
Blog Series Overview:
The Cloud Educational Blog Series is sponsored and hosted by the HEUG Campus Community Advisory Group, with the intention to start educating and socializing the user community on Cloud terminology, case studies, and relevant resources related to Cloud technologies and innovations, as many universities are beginning to think about Cloud solutions for their Student Information Systems. To view other articles in the series, please go to the Article Index for the Cloud Blog Series.
Article Overview:
This article represents our first article in the Campus Community Advisory Group’s new Cloud Educational Blog Series. As many universities are beginning to think about Cloud solutions for their Student Information Systems, the intent of this article is to start over-viewing some basic Cloud terminology and concepts in an effort to baseline the community’s understanding of commonly used terminology in the Cloud space.
Article:
Over the last few years the word “Cloud” has been used more and more commonly in the technology space, and I assume that, increasingly, we have all been in meetings or presentations where someone – internal or external to your institution – has said phrases like, “put it in the Cloud” or “it’s in the Cloud.” But what do those phrases mean, and what is the Cloud?
While the word “Cloud” generically refers to a product or service offering that is not locally hosted by the customer, it is often used analogously, and sometimes ambiguously, to refer to many types of products or services. There are three main, and most common, types of Cloud products – Software as a Service, Platform as a Service, and Infrastructure as a Service. Each of these products have different intentions and functionalities, although often a cloud solution will involve more than just one type of Cloud product. To start baselining more commonly used terminology, the below sections overview, at a high-level, some of the most commonly used terms in the Cloud space today. Future blog articles in the new blog series, sponsored by the HEUG Campus Community Advisory Group, will go into much more detail on each of the below referenced areas, as well as offer additional insight, such as providing some implementation methodologies and case studies.
Software as a Service (SaaS)
Software as a Service (SaaS), most commonly refers to a cloud offering where a software product is hosted and supported off-premise by a vendor. In this model, an external party – usually a vendor – offers a software solution that they host either in their own data center or in a third-party data center in the Cloud. This offering removes the need for customers to run and maintain local versions of a software application on their own infrastructure. However, most often, SaaS products do not offer easy access to modify the code-line of the application, but many of these product offerings do offer ways to easily integrate with other systems using Application Programming Interfaces (APIs), or often, they will allow the creation of bolt-on functionality using a Platform as a Service (PaaS) product.
Platform as a Service (PaaS)
Platform as a Service (PaaS), most commonly refers to a Cloud product offering where hardware and software development tools are offered, and hosted, off-premise by a vendor. PaaS products provide a common platform to develop bolt-on functionality or APIs, and often these products allow multiple language choices and provide a high level of interoperability. Additionally, often, the use of a PaaS product with a SaaS product allows a customer to more seamlessly build bolt-on functionality, and provide and consume APIs, in a manner that allows the customer to more easily extend their SaaS application and still provide relatively seamless functionality, which may not be directly available in the stock SaaS application, to their customers.
Infrastructure as a Service (IaaS)
Infrastructure as a Service (IaaS), most commonly refers to a Cloud offering where a customer’s infrastructure/component layers, such as application servers, web servers, databases, and networking hardware are hosted and supported off-premise by a vendor in the vendor’s datacenter, or sometimes, in a data center that the vendor contracts with. This offering removes the need for customers to host and run all, or some, of their infrastructure components in their own data centers.
Lift and Shift
Lift and shift is a methodology most commonly related to the use of an IaaS product, where a customer clones, or closely mimics, their existing infrastructure for an on premise software application in the Cloud using an Infrastructure as a Service (IaaS) product. This is an example of utilizing a cloud strategy for software applications that still need to be installed, supported, and maintained by the customer, but the infrastructure, such as the servers and database, can be hosted and supported in a vendor’s data center.