Download Microsoft.AZ-900.PrepAway.2021-05-17.208q.tqb

Box 1: NoA PaaS solution does not provide access to the operating system.  The Azure Web Apps service provides an environment for you to host your web applications.  Behind the scenes, the web apps are hosted on virtual machines running IIS.  However, you have no direct access to the virtual machine, the operating system or IIS. Box 2: YesA PaaS solution that hosts web apps in Azure does provide the ability to scale the platform automatically. This is known as autoscaling.  Behind the scenes, the web apps are hosted on virtual machines running IIS.  Autoscaling means adding more load balanced virtual machines to host the web apps. Box 3: YesPaaS provides a framework that developers can build upon to develop or customize cloud-based applications. PaaS development tools can cut the time it takes to code new apps with pre-coded application components built into the platform, such as workflow, directory services, security features, search and so on. References:https://azure.microsoft.com/en-gb/overview/what-is-paas/

Fault tolerance is the ability of a system to continue to function in the event of a failure of some of its components. In this question, you could have servers that are replicated across datacenters. Availability zones expand the level of control you have to maintain the availability of the applications and data on your VMs. Availability Zones are unique physical locations within an Azure region. Each zone is made up of one or more datacenters equipped with independent power, cooling, and networking. To ensure resiliency, there are a minimum of three separate zones in all enabled regions. The physical separation of Availability Zones within a region protects applications and data from datacenter failures. With Availability Zones, Azure offers industry best 99.99% VM uptime SLA. By architecting your solutions to use replicated VMs in zones, you can protect your applications and data from the loss of a datacenter. If one zone is compromised, then replicated apps and data are instantly available in another zone. References:https://docs.microsoft.com/en-us/azure/virtual-machines/windows/manage-availability

A private cloud is hosted in your datacenter. Therefore, you cannot close your datacenter if you are using a private cloud. A public cloud is hosted externally, for example, in Microsoft Azure. An organization that hosts its infrastructure in a public cloud can close its data center. Public cloud is the most common deployment model. In this case, you have no local hardware to manage or keep up-to-date – everything runs on your cloud provider's hardware.  Microsoft Azure is an example of a public cloud provider. In a private cloud, you create a cloud environment in your own datacenter and provide self-service access to compute resources to users in your organization. This offers a simulation of a public cloud to your users, but you remain completely responsible for the purchase and maintenance of the hardware and software services you provide. Reference:https://docs.microsoft.com/en-gb/learn/modules/principles-cloud-computing/4-cloud-deployment-models