On Premise means the phone systems is hosted on your site. Typically, you own all of the handsets
In the purest sense this means all equipment is hosted elsewhere and delivered across the internet. Costs are monthly based on use. Physical handsets are usually an additional upfront cost.
If you have a traditional phone system that you are happy with but want some of the features offered by cloud-based technology then you might use a VoiP enabled PBX. This gives you a hybrid solution
PBX stands for Private Branch Exchange - a private telephone network used within an organisation. PBX phone system users can communicate internally (within the organisation) and externally (with the outside world), using communication channels like Voice over IP, SIP Trunks or analogue.
Voice over Internet Protocol – uses technology like SIP Trunks to enable you to use the internet to make and receive calls
Session Initiation Protocol – a technology that enables calls to made over the internet
Integrated Services Digital Network – a set of communication standards for the digital transmission of voice, video, data etc over the traditional phone network
Telephony Application Programme Interface – the ability to communicate between a computer and telephone system
The ability to communicate wherever you are, on whatever device. Includes conferencing, video, instant messaging and more