Unified Communications is the merger of instant messaging, telephony, call control, speech recognition, data sharing, video conferencing, and presence information. It allows someone to send a message one way and receive it via another.
a LAN
Unified Communications
Unified communications systems typically include the means to integrate real-time or near-real time unified messaging, collaboration and interactive systems. For example, a single user can access a variety of communication applications such as e-mail, SMS, video, fax, voice, and others through a single user mailbox.
Unified communications are things such as cell phones and webcams, which provide you with the opportunity to speak or communicate with other people that are far away from you.
Wikipedia is a great source of information, and has an extensive article on Unified Communications. The Microsoft website also has a lot of information.
The Cisco 7941g is what is known as a unified IP phone used for business communications. It is a landline telephone that also features a grayscale LCD screen.
I think you may mean CUCM, which is the "Cisco Unified Communications Manager, "the "brains" of a Cisco Unified Communications system. The product used to be called "Cisco Unified Call Manager" and before that just "Call Manager."
Unified communications really means the instant, real-time delivery of messages to anyone, anywhere. It is made possible through the many technological products we as a society have developed.
INFORMATION & COMMUNICATIONS TECHNOLOGY, UNIFIED COMMUNICATIONS, A fusion of DATA Communications, AUDIO, VIDEO & MultimediaCommunication Technologies.
Cisco Unified Communications allows voice and video conferencing. The various types of software will support audio, data, streaming video, and mobile applications.
Unified communications became an accepted business practice in the 1990's with the development of voice mail and email systems. They continue to develop as technology develops and now contain things like instant messaging and text messages.
CCNA stands for Cisco Certified Network Associate. Topics that the CCNA training videos cover include Basic Voice Communications, Cisco Unified Communications Management, and at least four other topics.