What Does Telephone Company Mean?
A telephone company (telco) provides telephone and data communication services. Most telephone companies offer Internet/telephone packages for a fixed monthly fee. Bundled telephony services are usually cheaper than individual services.
This term is also known as telecommunications operator, communications service provider (CSP) and, in the U.S., local exchange carrier (LEC).
Techopedia Explains Telephone Company
A cellular telephone company (cellco) is the wireless counterpart to telco.