What is difference between SaaS, PaaS and laaS?

Question

What is the difference between:

1. using "the Command-line interface to the OpenStack APIs" through the command "openstack"
   and
2. using the separate APIs of the different components (for example using the command-line interface to the Neutron APIs directly)?

Advantages and disadvantages?

Answer 1

IaaS : Infrastructure as a solution is a concept by which hardware components such as compute server, storage and networking components are provided. In this case, customer/client decides what OS should be installed. IaaS is considered at bare metal.
PaaS: When an OS is installed in bare metal components it becomes platform as a service and user can launch Virtual machine. And he/she can install applications within the VM as per requirement.
SaaS : In SaaS, services are provided to customer/client such as Office365 through cloud platform. In this special case user is taking a particular service. User does not bother in which type of platform services are running.

Answer 2

SaaS: Software as a Service

It simply means running applications at public clouds. The user uses these apps via the Internet. These apps are maintained by the Service Provider. Some e.g., of Service Providers, are SalesForce, Microsoft(Office 365), Oracle, Google(Google Apps), etc.

Salesforce was the first company to transform the world of Saas, and from that point, other companies have seen potential in this market and launched their apps.

Iaas: Infrastructure as a Service

It provides an environment for developers to build applications that users can use. IaaS includes:-

Users create virtual machines (VMs) on demand.
From a library of VM images.

PaaS: Platform as a Service

This is somewhat similar to IaaS but the difference is:

Developers provide an application which the platform runs.
They don’t directly create VMs.

You would be thinking that PaaS is simple and that is why mostly used. But this is not true. IaaS is 10 times popular than PaaS. Developers want to have more control over the resources.

https://www.esds.co.in/blog/iaas-vs-daas-vs-paas-vs-saas-which-should-you-choose/