A u.s government organization that puts forth standards for federal agencies to use nist defines cloud computing as a model for enabling in ubiquitous convenient on demand network access to a shared pool of configurable resources like networks, servers, storage, applications and services that can be rapidly provisioned and Released with minimal management effort or service provider interaction. Now, what does that exactly mean it’s, a pretty lengthy definition and really what that breaks down to is cloud computing can be defined by these definitions right here: broad network access on demand, self service, multi, tenancy, rapid elasticity and scalability resource pooling and measured or metered service. So these all combine to form cloud computing and we’ll talk about each of these in detail. Broad network access means that the cloud provider can provide their services without being bottlenecked or being restricted by bandwidth, so they can be accessed from geographically dispersed locations. Usually this means through the internet. That means you can sell cloud services to customers across the globe. Customers can access their data or their applications, regardless of where the actual data is physically stored. On demand service allows customers to purchase and scale their needs with little or no communication with the provider so they’re able to change their requirements without having to perform a lengthy contractual conversation with the cloud service provider. They can just adjust their settings on their own, so they could increase the amount of storage they need if you decrease that storage or if it’s, an application increase the amount of usage they’re using with that application.

It’S, all up to the customer and it’s put up to the customer without having the customer interact with the service provider. Multi tenancy is a concept where one piece of hardware is used to host many different customers. So this is what makes cloud computing financially viable. Customers are provided with a portion of a piece of hardware, so whether that’s in data storage, a customer would be provided a portion of that data storage and the cloud service provider would host multiple customers using that same piece of hardware. So they’d have one data storage device and then they would provision that out to many different customers. This makes this justifies the cost for the cloud service provider. They host these expensive pieces of hardware. These expensive servers server racks, they pay for the security and the power for those security racks, and then they provision those out to multiple customers. Each chart charging each customer a portion of the price with virtualization cloud service providers can provision out multiple operating systems or multiple instances of a cloud application or web application, and this makes the whole cost the investment that the cloud service provider put in to obtain these Resources justified and it allows them to make money and that’s the whole structure of cloud computing. Rapid elasticity and scalability allows resources to be scaled and adjusted depending on the customer’s needs. So if the customer requires more processing, speed or a better server, if they have maybe a dedicated server, then the cloud service provider can rapidly change their needs, change the offering provided to the cloud customer.

This can be an easy examples. With data storage say a cloud customer has a hundred gigabytes of online cloud storage, they’re reaching that hundred gigabyte limit, and they want to store more files. That limit can just be increased easily by allocating more storage space to the customer and that that can be done very very quickly through virtualization through other supporting technologies. Resource pooling means that cloud service providers can use their components in a cost effective way. They can allocate resources on an as needed basis. They can pull resources to meet higher spikes in demand and they can use their resources to meet the individual needs of their cloud customers in a rapidly changing environment. So the cloud service provider is investing and they maintain a data center that has multiple pieces of very expensive hardware and they need to use these concepts like resource pooling, a multi, tenancy, etc. To allocate these resources effectively and in a manner that will make the cloud service fighter money and then make that service very cheap for the cloud, customer, measured or metered service means that the cloud customer only pays for what they’re purchasing. So this is much like a power company’s power meter if you’ve seen a one of those meters that sits outside of a building and measures the amount of kilowatts per hour or not entirely sure on the the measurement but measures the electricity going into the building. Okay, that meter is very similar to what a cloud service provider would offer oftentimes with uh cloud computing it’s more along lines of how much data they’re using how much storage space do they require what’s the processing power they need for the server that they’re purchasing or How much? How are they using their web application uh? Those are the measurements used to charge the cloud customers, but the cloud customers are only charged for what they use.

They they’re not charged for excess or, if they’re charged for excess, it’s it’s at a much lower rate than if the cloud customer or much cheaper rate than if the cloud customer were to purchase their all of that hardware on their own. So basically, the cloud service provider measures or puts a meter on the services that they’re providing to the cloud customer and the cloud customer is charged based on what they use. For many of i mean this is going to be review. It should be confidentiality, integrity and availability are three terms that we’re going to be hitting on multiple times throughout the course. Just as a review. Confidentiality is the protection of the data from unauthorized access. This usually involves some form of encryption to ensure that the data is not released or is not exposed to people who are not authorized to view it. Data integrity is the actual integrity and accuracy of the data to make sure that the files maintain their structure and the data maintains its structure. It does not change over time, either through malicious attacks or just through data decay. This is uh when we talk about data in motion. Data integrity involves the accuracy of the data transmission and ensures that data is protected from any unauthorized alterations and the availability is how how information is provided to the cloud customer and if that information is provided on an uninterrupted basis.

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