Business telephone systems are referred as the system of multiple telephone lines or a mechanism that is used to connect from one telephone to another in the business premises. The multiple lines used by different users can be accessed by a single user at a point of ‘’station’’. Business telephone systems are categorized into different types depending upon the procedure for working or operations. Under PBX systems the station user handles the calls or transfers the calls to a particular line of user, whereas for the key systems the line buttons are operated to call to a particular line. Under the hybrid system of telephone, a particular line is identified by the special call appearance button features.
Business phone systems distinguish from the business telephone system because it a cordless means of communication unlike the latter system. Today due to the advent of new technologies and changing trends in telecommunication industry business phone systems can be categorized into four categories and they are the VOIP system, PBX system, KSU and private brands such as Comial, Lucent, Motorola and many other brands. The VOIP allows the user to receive and make calls through the internet system. Most of these systems have the feature of LAN access, e-mail integrating, recording the calls, forwarding the calls and computer access management system.