A linked clone is a copy of a virtual machine that shares virtual disks with the parent virtual machine in an ongoing manner.
Because a linked clone is made from a snapshot of the parent, disk space is conserved and multiple virtual machines can use the same software installation. All files available on the parent at the moment you take the snapshot continue to remain available to the linked clone.
Ongoing changes to the virtual disk of the parent do not affect the linked clone, and changes to the disk of the linked clone do not affect the parent. A linked clone must have access to the parent. Without access to the parent, you cannot use a linked clone.
Because linked clones are created swiftly, you can create a unique virtual machine for each task. You can also share a virtual machine with other users by storing the virtual machine on your local network where other users can quickly make a linked clone. For example, a support team can reproduce a bug in a virtual machine, and an engineer can quickly make a linked clone of that virtual machine to work on the bug.
You can make a linked clone from a linked clone, but the performance of the linked clone degrades. If you make a full clone from a linked clone, the full clone is an independent virtual machine that does not require access to the linked clone or its parent. You should make a linked clone of the parent virtual machine, if possible.