转自wikipedia:
On-premises software (often abbreviated as on-prem software) is installed and run on computers on the premises (in the building) of the person or organisation using the software, rather than at a remote facility, such as at a server farm or cloud somewhere on the internet. On-premises software is sometimes referred to as “shrinkwrap” software, and off-premises software is commonly called “software as a service” or “computing in the cloud”.