VoIP-Voice over Internet Protocol

• Voice over Internet Protocol is a category of hardware and software that enables people to use the Internet as the transmission medium for telephone calls by sending voice data in packets using IP rather than by traditional circuit transmissions of the Public Switched Telephone Network (PSTN).

PBX – Private Branch Exchange

• PBX is a telephone system within an enterprise that switches calls between enterprise users on local lines while allowing all users to share a certain number of external phone
• Most medium-sized and larger companies use a PBX because it’s much less expensive than connecting an external telephone line to every telephone in the organization. In addition, it’s easier to call someone within a PBX because the number you need to dial is typically just 3 or 4 digits.