What Is the Definition of ISP?

An ISP, or an Internet Service Provider, is a company that provides access to the Internet for their customers. But an ISP does much more than that. Some ISPs provide customers email addresses, and still others offer data file storage plus a host of other services.

Significance

The Internet is actually a collection of many networks. To keep some sort of order, a single uniform system for addressing is required. For this, an addressing scheme is used which does not depend on the physical address. This addressing is specified by an Internet Protocol, or IP. It provides a 32-bit IP address to every website on the Internet.

Function

Conceptually, each 32-bit IP address is divided into two parts, a prefix and a suffix. The prefix identifies the physical network to which the node is connected; the suffix identifies the individual computer. For networks connected to the global Internet, an organization obtains network numbers from the communication company that supplies Internet connections. These companies are called Internet Service Providers.

History

ISPs came into prominence in 1990s. ISPs coordinate with a central organization called IANA (Internet Assigned Number Authority) to ensure that each network prefix is unique throughout the entire Internet. An ISP is granted a large range of addresses and then subdivides the addresses, giving a range to a household or a small business. The customers are connected via dial-up modem, DSL or cable modem to the ISP. An Internet Service Provider is also called Internet Access Provider, or IAP, at some places.

Types

The Internet is divided into international and national ISPs. National ISPs are divided into regional ISPs, and regional ISPs into local ISPs. This helps in reducing the size of the routing table.

Features

There are also Wireless Internet Service Providers, or WISPs, that provide access to the Internet through a wireless network. Many ISPs not only provide the accessibility but also some related services like email and Web hosting. Some prominent providers are Netcom, Erols and Concentric. These ISPs charge a flat monthly rate for providing Internet access. Some space on the ISP server is reserved for the customers to maintain websites. Some ISPs are commercial, while others are run by governments, and educational and non-profit organizations.

Considerations

Virtual ISPs, or vISPs, are also available. A vISP purchases the services from another ISP. This is also called wholesale ISP. Not all ISPs charge for their service: There are also freenets, or free ISPs. They generally have a bar of advertisement that is running in the browser as long as the user is connected to the Internet. They charge from the advertisers but not from the Internet users.