4.1 - CompTIA A+ Core 1

Virtual Machines (VMs)

Virtual guest computers that run inside a physical (host) computer using hypervisor software.

Sandbox

An isolated environment with no connections to real-world production systems or devices, used to test software.

Application Virtualization

Allows developers to test code in a safe environment identical to where it will be used.

Legacy Software/OS

Used to run different application versions or applications only compatible with older OS versions.

Cross-platform Virtualization

Enables running different operating systems simultaneously on the same system.

VM Escape

When malware compromises the hypervisor to move from one guest OS to another.

Guest OS Security

Treat guest VMs like real computers, using traditional security controls.

Shared Network Address

VM configuration where virtual machines use the same IP as their physical host.

Bridged Network Address

VM configured as a device on the host’s network.

Memory Usage in VMs

VMs require a large quantity of memory; ensure host has more memory than VMs.

Type 1 Hypervisor

A bare metal hypervisor that interacts directly with underlying machine hardware.

Type 2 Hypervisor

A hosted hypervisor that interacts with virtual machines via the host machine’s operating system.

Virtual Desktop Infrastructure (VDI)

A technology that allows desktops to be virtualized and delivered to users over a network.

Shared Resources

Resources that are shared with a public cloud provider, where the underlying cloud infrastructure is owned by a third party.

Dedicated Resources

Resources that are not shared, where an organization builds its own cloud environment/datacenter and pays for everything up front.

Metered Utilization

Payment of cloud services based on the amount of service used, typically including costs for upload, storage, and download.

Ingress

Refers to data entering a cloud environment, often uncharged by cloud providers.

Egress

Refers to data leaving a cloud environment, often charged by cloud providers.

Non-metered utilization

Payment for cloud services independent of usage, typically managed by paying monthly for a specific block/quantity of storage.

Rapid Elasticity

A characteristic of cloud computing that allows platforms to scale up or down as needed.

High Availability

Refers to cloud environments’ high redundancy, ensuring that systems are always available without significant downtime.

File Synchronization

Refers to information/files being duplicated across multiple cloud locations.

Multitenancy

Refers to multiple customers of a cloud vendor using the same cloud computing resources.