LASR X is a web-based application and is licensed to one device at a time with a normal account. You can switch devices at any time or increase your device limit for a small fee from your account settings.
LASR Classic must be installed on a computer (or other device running a supported version of Windows), and each license is limited to running on one computer at a time. If you do get a new computer, as you can move LASR to a different computer using the same installation link and license key.
You can move the license once every 30 days, and plugins will migrate with the license. If you wish to run LASR Classic on two different computers regularly, you will need a second license.