Office phones need to be more complex than home phone systems. Office phones need to manage multiple incoming calls, detailed data concerning callers and call transfers. There are a variety of phone systems that businesses can choose based on their needs, size, and technological limitations. New electronics and Internet systems are continuing to give us more innovative systems to choose from.
PBX (private branch exchange) systems are one of the traditional types of office phone networks and are useful for larger companies, especially for those with more than 40 employees in one building. Once large, today's PBX systems are small network devices that can be kept at the reception desk or server room. They come with the ability to handle large numbers of callers and can be programmed with different business department configurations to make transferring easier.
Key systems are designed for smaller businesses -- those that operate with between five and 40 employees. They have central control units that manage and transfer calls while allowing extensions to operate and keeping phone calls private within the network. They are not designed to carry a heavy load of calls like PBX systems, or to offer the same complex call management, but differences are beginning to fade. Technology has made many key systems more like PBX units by adding more possible features.
KSU-less systems are designed for small offices with fewer than 10 people. There is no central managing unit in KSU-less systems: every phone has the capability to take and transfer calls on its own. These phones are much easier to move around than larger phone network, but businesses often need to do much of the installation themselves.
Handheld phones in business are typically smartphones with email and document capabilities as well as cell phone features. These phone are very expensive, even on company plans, so some businesses decide to support only handhelds, which can be used on the go and in the office.
VoIP stands for Voice over Internet Protocol, a phone technology that streams phone data online instead of using traditional phone lines. These systems are less expensive than landlines, but they require dedicated phone equipment from the provider.