Laas, Paas, SaaS

IaaS
Infrastructure-as-a-service, or IaaS, is a step away from on-premises infrastructure. It’s a pay-as-you-go service where a third party provides you with infrastructure services, like storage and virtualization, as you need them, via a cloud, through the internet.

As the user, you are responsible for the operating system and any data, applications, middleware, and runtimes, but a provider gives you access to, and management of, the network, servers, virtualization, and storage you need.

You don’t have to maintain or update your own on-site datacenter because the provider does it for you. Instead, you access and control the infrastructure via an application programming interface (API) or dashboard.

IaaS gives you flexibility to purchase only the components you need and scale them up or down as needed. There’s low overhead and no maintenance costs, making IaaS a very affordable option.

One way to use IaaS would be as a quick, flexible way to build up and take down and development and testing environments. You can use only the infrastructure you need to create your development environment—and scale it up or down—for as long as you need it, and then you can stop when you’re finished, paying only for what you use.

The main drawbacks to IaaS are the possibilities of provider security issues, multi-tenant systems where the provider must share infrastructure resources with multiple clients, and service reliability. These drawbacks can be avoided by choosing a reliable and trustworthy provider with a solid history and reputation.

Public cloud providers such as AWS, Microsoft Azure, and Google Cloud are examples of IaaS.

PaaS
Platform-as-a-service (PaaS) is another step further from full, on-premise infrastructure management. It is where a provider hosts the hardware and software on its own infrastructure and delivers this platform to the user as an integrated solution, solution stack, or service through an internet connection.

Primarily useful for developers and programmers, PaaS allows the user to develop, run, and manage their own apps without having to build and maintain the infrastructure or platform usually associated with the process.

You write the code, build, and manage your apps, but you do it without the headaches of software updates or hardware maintenance. The environment to build and deploy is provided for you.

PaaS is a way that developers can create a framework to build and customize their web-based applications on. Developers can use built-in software components to create their applications, which cuts down on the amount of code they have to write themselves.

A few examples of PaaS are AWS Elastic Beanstalk, Heroku, and Red Hat OpenShift.

SaaS
Software-as-a-service (SaaS), also known as cloud application services, is the most comprehensive form of cloud computing services, delivering an entire application that is managed by a provider, via a web browser.

Software updates, bug fixes, and general software maintenance are handled by the provider and the user connects to the app via a dashboard or API. There’s no installation of the software on individual machines and group access to the program is smoother and more reliable.

You’re already familiar with a form of SaaS if you have an email account with a web-based service like Outlook or Gmail, for example, as you can log into your account and get your email from any computer, anywhere.

SaaS is a great option for small businesses who don’t have the staff or bandwidth to handle software installation and updates, as well as for applications that don’t require much customization or that will only be used periodically.

What SaaS saves you in time and maintenance, however, it could cost you in control, security, and performance, so it’s important to choose a provider you can trust.

Dropbox, Salesforce, Google Apps, and Red Hat Insights are some examples of SaaS.

출저: Red Hat