This is the most trivial licensing scenario: the licensee receives a license key, which can be used/activated only on one device (e.g., Windows, MAC). In this context, this license can be considered an installation license, since it requires the generation of a unique device id.
This license key can not be activated on a different installation, unless it is first unassigned from the initial installation. This ensures that a license key can be activated only on one installation at any given moment.
Floating (also known as concurrent) licensing models are based on the number of maximum installations that are allowed to be simultaneously active. Practically, this means that there is no restriction on the number of devices that the software can be installed and activated using the same license key. However, upon program start, the licensing service checks if there are available tokens. If not, then this client has to wait until another disconnects in order to use the software.
Obviously, floating scenarios require a central component/authority for session management (making sure the number of allowed sessions is not exceeded), that standalone applications are lacking. This is where SLASCONE comes into play, undertaking this role.
It is important to underline, that named and floating models are not mutually exclusive. SLASCONE allows you to create named and floating license keys, allowing you to offer both models for your end-customers.
Typically, vendors use the expiration date to prevent a perpetual usage of the software. However, there are cases in which the customer is allowed to perpetually use software Version X, but not Version X+1. Such scenarios can be implemented in SLASCONE.