Internet service provider
An internet service provider (ISP) is a company who provides customers with access to the world wide web. There are many varieties of internet service providers, some focusing on consumers, businesses (small, mid cap, large), government organizations, non-profit organizations, educational institutions, and/or other ISPs. ISPs may offer access via DSL, cable modem, dialup, fiber optic network, cellular, satellite, or power line communications among others. If an ISP is not itself a tier 1 provider, then it must lease connections through another provider to connect to outside networks. Most of the tier 1 providers are telephone companies such as AT&T.