- [Narrator] Cloud computing is the information storage
and processing model of the future.
In the last video you learned
how virtualization was a major advance in the industry
that evolved over time from mainframe computing
to the client server model,
and eventually developed the virtualization technology
that allowed the use of the client server model
on effeciently shared hardware.
Cloud computing is the next logical evolution
in the enterprise information technology world.
Virtualization made computing hardware a commodity.
Cloud commodity simply allows us to make hardware
a complete abstraction so that the engineers
and developers who manage servers and write code
don't need to know the details
of managing the underlying hardware platform.
In many cases that platform may be managed
by a completely separate company.
Cloud computing simply defined
is the delivery of computing resources
over a network, such as the internet, as a service.
The cloud offers many benefits to organizations.
It provides flexibility and scalability
that organizations need to shift computing resources
to areas of emerging need.
It increases agility by making it possible
to rapidly provision IT resources for new projects,
and the cloud boosts cost effectiveness
by achieving economies of scale.
Let's look at three models of cloud computing:
private cloud, public cloud, and hybrid cloud.
All three of these models
allow organizations to achieve
the benefits of cloud computing in different ways.
Organizations using the private cloud model
want to gain the flexibility, scalability,
agility, and cost effective of the cloud
but do not want to share computing resources
with other organizations.
In the private cloud approach
an organization builds and runs
its own cloud infrastructure or pays another organization
to do so on its behalf.
The public cloud uses a different approach,
the shared tenancy model.
In this approach cloud providers build
massive infrastructures in their data centers
and then make those resources available to all comers.
The same physical hardware may be running workloads
for many different customers at the same time.
Organizations adopting a hybrid cloud approach
use a combination of public and private cloud computing.
In this model, they may use the public cloud
for some computing workloads,
but they also operate their own private cloud
for other workloads, often because
of data sensitivity concerns.
When organizations use public cloud resources,
they must understand that security in the public cloud
follows a shared responsibility model.
Depending upon the nature of the cloud service,
the cloud provider is responsible for some areas
of security while the customer is responsible
for other areas.
For example, if you purchase a cloud storage service,
it's your responsibility to know what data
you're sending to that service,
and probably to configure access control policies
that say who may access your data.
It's the provider's responsibility
to encrypt data under their care
and correctly implement your access control policies.
When you take the Security+ exam,
you should remember that no one cloud model
is inherently superior to the others.
Organizations may wish to use
a public cloud-heavy approach
to achieve greater cost savings,
while other organizations may have regulatory requirements
that prohibit the use of shared tenancy computing.