The telephone is probably the most important and the most used method of communication today. All over the world, telephones are being used extensively, whether in homes or in offices. When it comes to office phone systems, the system is particularly designed so that any number of users can use and share the same telephone lines, rather than having to use individual phones. Telephone systems like these are specifically designed for use by several people in a single location, like companies and large offices. Using these types of phone systems can mean lesser expenses for businesses, since it is proven to be more cost-effective than using regular telephone systems.

PBX - The PBX telephone system, or Private Branch Exchange, are phone systems which are designed specifically for corporate use in offices. The main purpose of a private branch exchange system is to create a private communication network among all those who use and share the external telephone lines. PBX systems are ideal for large and medium-sized companies and businesses. What makes this phone system cost-effective is that users can now share a few external phone lines, as compared to having all individual users having their own external lines.

Using a PBX phone system allows a person to communicate with another user on the telephone network by just dialing a 3 or 4 digit extension number. Plus, PBX systems also have additional features like voicemail, reminders, screen displays, and options to screen all calls. PBX phone services for offices may also include automated answering services, auto-generated messages for callers, and live call transferring.

Automated Attendants - The Automated Attendant is an accessory used in most office phone systems for answering phone calls by way of automatically generating electronic messages. Using this accessory or tool, callers will be allowed to route themselves within the phone system through a series of menu prompts. Office voice mail systems are usually equipped with a basic automated attendant system.

Automated Call Distributor - Another phone accessory commonly used in office phone systems is the Automated Call Distributor or ACD. This accessory provides an efficient way of routing all incoming calls between programmed extension numbers. The most common locations for Automated Call Distribution systems are call centers, or any other office or location that has to process several incoming calls all at the same time.

Computer Telephony Integration - The CTI, or Computer Telephony Integration tool, is used for connecting an existing phone system to a computer, or computer network. Important information is automatically retrieved from incoming calls, routed to the computers, where the data is processed for practical business purposes. There is another tool called the Key System Unit, or KSU, which contains useful features like call forwarding, extension dialing, and options for using voice mail. VOIP systems, or Voice Over Internet Protocol, allows users to communicate with other VOIP systems and use digital data through the Internet.

These office telephone systems are incorporated into the standard system of analog telephones, fax machines, cordless and cellular phones, using a traditional telephone network, and they also have the option of communicating through the Internet using VOIP.