VMware Workstation Player Glossary: Virtualization, Networking, Storage, and VM Features

Learn essential VMware Workstation Player terms covering virtual machines, VM files, virtual disks, networking modes, guest integration, USB devices, and troubleshooting.

This glossary explains the concepts and files you encounter when creating, running, and troubleshooting virtual machines in VMware Workstation Player. It is intended for beginners and intermediate users who understand basic computers, operating systems, files, storage, and networks.

Virtualization foundations

Virtual machine, host, and guest

A virtual machine (VM) is a software-defined computer. It has virtual hardware such as processors, memory, disks, and network adapters, and it can run an operating system and applications.

The physical host computer is the real computer providing CPU, memory, storage, and other hardware. Its host operating system is the operating system installed directly on that computer. The guest operating system is installed inside a VM and runs on the virtual hardware presented by VMware Workstation Player.

For example, Windows may be the host operating system on a physical laptop while Ubuntu is the guest operating system inside a VM.

Hypervisors

A hypervisor is a software layer that creates and manages VMs. It presents virtual hardware to each VM and mediates access to physical resources so multiple operating systems can run on one computer.

Type 1 hypervisor: runs directly on physical hardware. These are commonly used in data centers and dedicated virtualization hosts.
Type 2 hypervisor: runs as an application on a conventional host operating system.

VMware Workstation Player is a hosted, or type 2, virtualization product. It runs on Windows or Linux and uses the host operating system to access the physical computer.

Virtual appliances

A virtual appliance is a prebuilt and preconfigured VM. It normally includes an operating system and application software, allowing it to be deployed without performing a conventional operating-system installation. Appliances are often distributed as OVA or OVF packages, or as a collection of VM files.

See Virtual Machine Explained for a simpler introduction, and the VMware Workstation Player course for related procedures.

VM identity and configuration

A Universal Unique Identifier (UUID) is an identifier used to distinguish one VM from another. VMware uses it when identifying a VM and some of its virtual hardware. Copying or moving VM files can raise identity questions, so preserve the UUID when software or licensing depends on it. See Virtual Machine UUID and keeping the same UUID.

The main VM configuration file has the .vmx extension. It stores settings such as virtual hardware, memory allocation, attached disks, network mode, and removable-device configuration.

The VM working directory is the folder containing the VM's configuration, virtual disks, logs, and state files. A representative directory may contain the following files, although exact contents vary by VMware product version, VM configuration, and current state:

File or extension	Purpose	Operational notes
`.vmx`	VM configuration	Defines virtual hardware and many VM settings.
`.vmdk`	Virtual disk	May be one file or several related descriptor and data files.
`vmware.log`	Message and runtime diagnostic log	Usually stored in the VM directory; older logs may also be present.
`.vmss`	Suspended-state data	Associated with preserving a running VM for later resumption.
`.vmsn`	Snapshot-state data	Stores state associated with a snapshot.
`.vmem`	VM memory-related data	May appear during suspend or snapshot operations, depending on configuration.
Paging, redo-log, and related files	Runtime or change-tracking support	Names and presence vary by feature and product version.

A redo log records disk changes separately from a base virtual disk, commonly while a snapshot or related disk state is active. Do not delete or rename VM files manually while the VM is running. For a broader file map, read Virtual Machine Files Overview.

Virtual disks and storage maintenance

A virtual disk is host-side file storage presented to the guest operating system as a disk drive. The standard extension is .vmdk. Depending on the disk type and settings, one virtual disk may be represented by one file or by multiple related files.

The guest operating system, its applications, and its user data are stored inside virtual disks. The guest sees a disk and partitions; the host sees files occupying space in the VM working directory.

Operation	Purpose	Changes guest-visible capacity	Changes host storage use	Follow-up action
Compact	Reclaims unused host-side space from a suitable virtual disk.	No	May reduce allocated host space.	Free space inside the guest may need to be prepared first; suitability depends on disk type.
Defragment	Improves the layout of virtual-disk data and may improve performance.	No	Usually reorganizes rather than reduces capacity.	Perform with the VM powered off and allow for host filesystem considerations.
Expand	Increases the capacity of a virtual disk.	Yes, after guest changes	Increases potential host storage use.	Extend the guest partition and filesystem separately.

Expanding a .vmdk does not automatically make the new space usable. The guest must detect the larger disk, and its partition and filesystem must then be extended using guest operating-system tools. Conversely, deleting files inside the guest does not necessarily return space to the host; compaction may be required. See Virtual Disks Explained, compacting a virtual hard disk, and defragmenting a virtual hard disk.

VM lifecycle and state management

Operation	What is preserved	Relevant files	When to use it	Key limitation or caution
Suspend	The current running state, including memory and open applications.	Often `.vmss` and memory-related files such as `.vmem`.	Pause work and resume later.	State depends on files remaining intact; it is not a clean operating-system shutdown.
Power off	No running state; the VM stops as if power were removed.	Normal configuration and disk files remain.	Perform a clean guest shutdown when possible, or stop an unresponsive VM.	Forced power off can risk guest filesystem corruption.
Snapshot	A point-in-time view of VM state and disk changes.	Often `.vmsn`, redo-log files, and related metadata.	Test changes and provide a rollback point.	Snapshots are not a complete backup and can consume storage over time.

Suspending preserves the active session for continuation. Powering off ends execution. A snapshot records a point-in-time state for later reversion or comparison. These operations are different even though each can involve additional files. File names and availability vary by product version and VM settings.

Guest installation and installation media

An ISO image is a file containing the structure and contents of an optical disc. Operating-system installers are commonly distributed as ISO images. When creating a VM, attach the ISO as virtual CD/DVD media, start the VM, and let the guest installer partition the virtual disk and install the operating system.

Easy Install is an assisted or automated guest-operating-system installation capability. It can enter installation information and reduce manual steps when the selected guest is supported. Support depends on the guest operating system and VMware Workstation Player version.

A small Linux distribution such as Damn Small Linux can illustrate a lightweight guest: attach its Linux ISO to a new VM, allocate modest virtual hardware, and boot from the image. The example does not imply that every old or small distribution supports Easy Install.

For removable-media setup, see Adding a CD-ROM Drive.

Hardware virtualization and CPU allocation

Intel VT-x is Intel's hardware-assisted virtualization technology. The corresponding AMD technology is AMD-V. These CPU features help a hypervisor run guest operating-system instructions efficiently and safely.

Hardware virtualization may be disabled in system firmware. If VMware reports that virtualization is unavailable, enter the computer's BIOS or UEFI setup, enable Intel VT-x or AMD-V, save the settings, and restart the host. Also check CPU support and whether another virtualization platform is using the capability. See Enabling VT-x.

Virtual SMP means symmetric multiprocessing for a VM: the VM is assigned multiple virtual processors. Add virtual CPUs only when the workload benefits from parallel processing and the host has enough available resources. More virtual CPUs can increase scheduling overhead and will not automatically make every application faster. See What Is Virtual SMP?.

Virtual networking components

A virtual network adapter is the network interface visible to the guest. It connects to VMware's virtual networking system rather than directly becoming a physical Ethernet or Wi-Fi device inside the guest.

A virtual switch is software that connects virtual network adapters, the host, virtual networking services, and sometimes a physical host adapter. A virtual DHCP server leases IP addresses to guests on VMware-managed private networks. A NAT device translates and routes traffic between a private VM network and an external network.

Mode	External network access	VM visibility on physical LAN	Typical IP addressing	Host-to-VM connectivity	Best use cases
Bridged	Directly through the host's physical adapter, subject to network policy.	Usually appears as a separate device.	Often receives its own address from the physical network's DHCP service, or uses a configured address.	Normally available according to LAN policy.	Testing a server or client that must be a peer on the LAN.
NAT	Yes, through host-mediated address translation.	Normally hidden behind the host's external identity.	Private address from a VMware virtual DHCP service.	Host access is commonly available; inbound access from the LAN needs additional configuration.	General guest internet access with reduced external exposure.
Host-only	Normally no external-network access.	Not visible on the physical LAN.	Private address from a host-only VMware DHCP service, if enabled.	Yes, between the host and participating VMs.	Isolated labs and host-to-guest testing.

Choose bridged networking when the VM must be independently reachable on a LAN. Choose NAT when it mainly needs outbound access while using a private address. Choose host-only networking when the host and VMs need a private lab without external access. Read Networking Configurations Overview for configuration guidance.

Host and guest integration features

VMware Tools is a collection of guest-side drivers and utilities. It can improve display resizing, mouse behavior, virtual hardware support, performance, file integration, and management operations. On Linux, installation may use a distribution-supported open-vm-tools package or another VMware Tools package. Prerequisites vary by distribution, packaging method, and Tools version; historically, some Linux installation scripts required Perl, a cross-platform programming language.

Feature	What it enables	Dependencies	Typical use
Copy and Paste	Clipboard transfer between host and guest applications.	Guest support, VMware Tools, and feature settings.	Move text or supported content during short tasks.
Drag-and-Drop	Graphical file transfer between host and guest where supported.	Guest desktop, VMware Tools, and compatibility.	Ad hoc file movement.
Shared folders	Ongoing access to selected host directories from the guest.	VMware Tools or supported guest integration and shared-folder configuration.	Work continuously on files stored in a host project directory.
Unity Mode	Displays supported guest applications alongside host desktop applications.	Product, host, guest, and VMware Tools support.	Use a guest application without viewing the entire guest desktop.
Autologin	Automatically signs in to a supported Windows guest environment.	Supported guest and configured credentials.	Convenient lab startup.
Enhanced virtual keyboard	Improves handling of international layouts and keyboards with additional keys.	Supported product, guest, and configuration.	Resolve non-US layout or special-key problems.

Shared folders provide continuing shared access; copy/paste and drag-and-drop are transfer workflows. They are not interchangeable. See What Are Shared Folders, Accessing a Shared Folder, Drag and Drop, Unity Mode, and Enhanced Virtual Keyboard Explained.

USB and removable-device concepts

An isochronous USB device requires time-sensitive data delivery. Audio devices, webcams, and some communication hardware are examples. Timing, bandwidth, and host support can affect how well these devices work in a guest.

USB Human Interface Devices (HIDs) include keyboards, mice, and game controllers. Some input devices remain controlled by the host because the host needs them for its own operation or because VMware treats them as host input rather than detachable guest USB devices. USB connection settings determine whether a supported device is connected to the host or guest.

Legacy Emulation Mode is an optical-drive compatibility setting used when a guest has communication problems with a physical CD/DVD device. It is relevant to physical optical-drive access, not to every ISO-image problem.

See Connecting USB HIDs, Configuring a USB Controller, and Choosing What Happens When You Connect USB Devices.

Logging and diagnostics

The VM message log contains warnings, errors, and runtime diagnostic information. The primary log is normally named vmware.log and is stored in the VM working directory.

Logs can help investigate driver problems, display errors, startup failures, device connection failures, and network configuration issues. When diagnosing a problem, reproduce it if safe, note the time, then inspect the newest log entries around that event. The VM directory connects the configuration file, virtual disks, state files, and logs in one location.

VM working directory
├── VM-name.vmx       configuration
├── VM-name.vmdk      virtual disk or disk descriptor
├── VM-name.vmss      suspended state, when present
├── VM-name.vmsn      snapshot state, when present
├── VM-name.vmem      memory-related state, when present
└── vmware.log        runtime messages and diagnostics

This is a representative layout, not a guarantee. File names, numbering, and presence vary with product version and VM activity. Never treat a log's absence of an error as proof that the underlying issue is impossible.

Programming and guest prerequisites

Perl is a cross-platform programming language. It is relevant to VMware terminology because some historical Linux VMware Tools installation scripts used Perl. Modern Linux installations may instead use distribution packages such as open-vm-tools. The exact prerequisites depend on the guest distribution, package method, and VMware Tools version.

Common troubleshooting applications

Virtualization unavailable: Check BIOS/UEFI for Intel VT-x or AMD-V, verify CPU support, and check for another virtualization platform using the feature.
Internet works but LAN devices cannot reach the VM: This is typical of NAT. Use bridged networking when the VM needs its own presence on the physical LAN.
Host and VM need private communication without internet: Select host-only networking and verify the host-only adapter and virtual DHCP service.
Copy/paste, drag-and-drop, display resizing, or shared folders fail: Install or update VMware Tools, restart its guest services if needed, and verify that the individual feature is supported and enabled.
Host disk remains full after guest deletion: Guest deletion does not necessarily shrink host-side .vmdk allocation. Determine whether compaction is appropriate.
Expanded disk has no usable extra space: Expand the virtual disk first, then extend the guest partition and filesystem.
Keyboard layout or special keys are wrong: Review enhanced virtual keyboard settings and distinguish keyboard mapping from USB HID passthrough.
Webcam, audio, or optical device fails: Review USB or optical-drive connection settings, consider Legacy Emulation Mode for physical CD/DVD issues, and inspect vmware.log.
Display, driver, or startup error has no clear interface message: Locate the VM working directory and inspect the message log near the time of failure.