Types of Cloud Services
IaaS
Infrastructure as a Service
The cloud provides the underlying platforms
Compute
Networking
Storage
The client handles and is responsible for all the rest. In other words, the cloud provides minimum infrastructure and we the clients of cloud are expected to take care of all the rest.
The most common example of IaaS is Virtual Machines.
The clouds provide the host machine, networking and disks.
The client creates the virtual machine, installs software on it, patches it, maintains it etc. So it is the responsibility of the client to make sure that the virtual machine is up and running, and the cloud has nothing to do with it.
PaaS
Platform as a Service
The cloud provides a platform for running apps.
Including Compute, networking, storage, runtime environment, scaling redundancy, security, updates, patching, maintenance etc.
The client just needs to bring the code to run
As a developer we just write the codes and upload it to cloud and the cloud takes care of all the rest.
Most common examples: Web Apps
The cloud provides the runtime for running web apps
The client uploads the code, and it just runs
The client has no access to the underlying virtual machines
SaaS
Software as a Service
A software running completely in the cloud.
The user doesn’t need to install anything on premises or on his machine
The provider of the software takes care of updates, patches, redundancy, scalability etc.
Common Examples: Office 365, SalesForce
We have no idea what is the infrastructure that Office 365 and Salesforce are running on
What are the virtual machines, what language are they developed in, what is a database and so on.
Types of Clouds
Public Cloud
The cloud is set up in the public network
Managed by large companies
Accessible through the internet
Available to all clients and users
Clients have no access to underlying infrastructure
Examples: AWS, Azure, Google Clouds, IBM Clouds
Private Cloud
A cloud set up in an organization’s premises
Managed by the organization’s IT team
Accessible only in the organization’s network
Available to users from the organizations
Uses private cloud infrastructure and engines
Contains a subset of the public cloud’s capabilities
Examples VMWare Cloud, Red Hat OpenShift Container Platform, Azure Stack
Used for privacy and security issues
Hybrid Cloud
A cloud set up in organization’s premises but also connected to the public cloud
Workload can be separated between the two clouds. For instance, sensitive data in the organization’s premises, public data in the public cloud.
So, for example, the organization can decide that the usernames, passwords and credit cards of its users will be stored inside the organization’s premises, but for example the professional profile of its users, such as the ones in LinkedIn will be stored in the public cloud.
Examples: Azure Arc, AWS Outposts
