Buying a "Lifetime with Portable USB Key" version allows you to move your registration quickly between different computers by simply plugging in the key. Site Licenses:
: To upgrade a V2 key to V3 or renew a license, use the USB License Key Updater tool.
: A one-time purchase that provides permanent access via a physical USB dongle.
: An annual subscription that can be renewed or upgraded to a lifetime license later.