The Public Switched Telephone Network (PSTN) is a widespread and fundamental telecoms infrastructure that has played a crucial role in facilitating voice communication for decades. This network forms the backbone of traditional landline phone services and connects a vast array of users worldwide.

PSTN operates through a system of interconnected carriers, including telecommunication companies and service providers. The primary function of the PSTN is to establish and maintain voice communication by utilizing standard telephone numbers. When a person initiates a call, the PSTN routes the call through a series of switches, exchanges, and transmission lines to ensure a reliable connection between the calling and receiving parties.

PSTN is its reliable and stable and provides a dependable means for individuals and businesses to connect globally. However, with the advent of digital technologies and the internet, alternative communication methods like Voice over Internet Protocol (VoIP) have gained popularity, challenging the traditional dominance of the PSTN.

Despite evolving technologies, the PSTN continues to serve as a critical component of global communication networks. It remains an integral part of telecommunications, especially in areas where digital infrastructure is still developing or in situations where the robustness of a wired network is essential for mission-critical communication.