Internet Service Provider (ISP)

An Internet Service Provider (ISP) is an entity or organization that delivers services for accessing the Internet. ISPs that most people are familiar with offer homes and businesses direct connectivity to the Internet via technologies such as DSL, cable, fiber optics, or wireless technologies.

But ISPs also deliver services such as Internet transit, domain name registration, web hosting, colocation, and others.

ISPs also comprise the backbone of the Internet in a multi-tiered hierarchical infrastructure.

https://en.wikipedia.org/wiki/Internet_service_provider