Task 1.3: Describe cloud service types

• AAzure Functions (serverless compute)

  Incorrect

  Functions would mean rewriting the apps, and they give the team no operating system to install the agents in.

• BAzure App Service (PaaS)

  Incorrect

  App Service doesn't let the team install agents in the operating system, and the apps would need adapting.

• CAzure Virtual Machines (IaaS)

  Correct

  IaaS gives full control of the operating system, so the servers and their agents can move as they are. Lift-and-shift migration is a standard IaaS scenario.

• DMicrosoft 365 (SaaS)

  Incorrect

  SaaS can't run the manufacturer's own server apps.

Lift-and-shift sets up cloud resources similar to the on-premises datacenter and moves the workloads across, which is why it's a typical IaaS scenario. PaaS and serverless hide the operating system, and SaaS offers someone else's finished app.

• AIaaS: build the app on VMs that the firm manages

  Incorrect

  IaaS would allow the custom logic, but the firm would manage the operating systems, which its developers want to avoid.

• BPaaS: build the app on a managed development platform

  Correct

  PaaS gives developers a framework to build and customize apps while the provider maintains the operating systems, middleware and tools.

• CSaaS: subscribe to a different finished ticketing app

  Incorrect

  SaaS is the least flexible model: a finished app can't take the firm's own workflow code.

• DPrivate cloud: run the vendor's app in a dedicated datacenter

  Incorrect

  A private cloud changes where the vendor's app runs and who it's dedicated to, not what the app can do.

SaaS is the easiest model to adopt but the least flexible, because you use the vendor's finished application. PaaS sits between IaaS and SaaS: developers write their own code, and the provider handles the platform underneath, including operating systems and middleware.

• AInfrastructure as a service (IaaS)

  Incorrect

  IaaS rents out compute, storage and networking that you configure yourself.

• BPlatform as a service (PaaS)

  Incorrect

  PaaS gives developers a managed platform to deploy their own apps.

• CSoftware as a service (SaaS)

  Correct

  SaaS supplies ready-made applications; Microsoft 365 and Dynamics 365 are Microsoft's own examples.

• DDesktop as a service

  Incorrect

  Desktop virtualization delivers whole desktops, as Azure Virtual Desktop does; these are finished business applications.

With SaaS you use a fully developed application, and the provider manages almost the whole stack. Microsoft lists Microsoft 365 and Dynamics 365 as SaaS examples, alongside email, messaging, productivity and finance applications.

• ASetting up the virtual network's address ranges and subnets

  Correct

  In IaaS the customer is responsible for network configuration, along with the operating systems and database and storage settings.

• BKeeping the datacenter's connection to the internet running

  Incorrect

  In IaaS the provider maintains network connectivity to the internet, along with the hardware and physical security.

• CLaying out the database files across the VMs' data disks

  Correct

  Database and storage configuration is listed among the customer's IaaS responsibilities.

• DSecuring the server halls against physical entry

  Incorrect

  Physical security is one of the things the provider keeps in IaaS.

• ERepairing failed hardware in the host servers

  Incorrect

  Maintaining the hardware stays with the cloud provider in IaaS.

With IaaS you're essentially renting hardware in a cloud datacenter. The provider maintains the hardware, the datacenter's internet connectivity and physical security; the customer handles everything else, including the operating systems, network configuration, and database and storage configuration.

• AThe provider, which maintains the application along with its infrastructure

  Correct

  In SaaS the provider handles infrastructure patching, application updates and availability.

• BThe team, by scheduling a maintenance window for its tenant

  Incorrect

  In SaaS the team doesn't install application versions; the provider maintains the application.

• CThe team's cloud administrator, through the platform's admin center

  Incorrect

  Installing new application releases isn't an admin-center task in SaaS; the provider ships each version.

• DThe provider and the team together, each patching half of the stack

  Incorrect

  Application maintenance isn't split in SaaS; the provider maintains the application stack.

SaaS has the lowest operational overhead for customers: the provider manages almost the whole application stack, including infrastructure, platform and application maintenance, and ships updates such as security fixes itself.

• AInfrastructure as a service (IaaS)

  Correct

  IaaS lets the team replicate established configurations quickly and start or shut down environments while keeping full control.

• BSoftware as a service (SaaS)

  Incorrect

  SaaS offers finished applications and no control over server configurations.

• CPlatform as a service (PaaS)

  Incorrect

  PaaS hides the operating system, so the team couldn't reproduce specific OS settings.

• DServerless functions

  Incorrect

  Serverless functions run code on events with no server configuration for the team to copy.

Testing and development is one of Microsoft's standard IaaS scenarios: teams rapidly replicate established configurations and start or shut down environments as needed, with complete control over the operating system.