Perpetual Model
A perpetual license allows the holder to use a specific version of a given software program continually with payment of a single fee. Essentially, it can be used indefinitely as they have purchased it and now own it.
Delivery Models
Usage Based Model
Software-as-a-Service (SaaS)
In this model, The software is hosted in the cloud and accessed by clients as a service on demand, via the Internet, using a ‘pay-as-you-go’ model.
On-Premises
Here the software is installed and runs on computers on the client’s premises, rather than at a remote facility such as a server farm or cloud.
Hybrid
In a hybrid model, the software is deployed as a SaaS service or as an on-premises solution, with the ability to switch from one to the other as needed. This model provides the advantages of both, while mitigating their potential drawbacks.