Domains are the main building blocks of Grid interaction. Each domain varies from a single Grid space of a few files or databases to an entire network. The owner of the domain can customize it to suit its needs or its fancy. Individual domains, and indeed, separate nodes and rooms within each domain can be functional, elaborate, cluttered, or sparse, but always following the rules and parameters set by the owner of the domain. Domains can be thought of as the “towns” of the Grid. Where the neighborhoods and buildings within a town are linked by geographical proximity, the locations (or nodes) within a domain are linked by virtue of a common Grid address. All locations within a domain have Grid addresses that are derived from the Grid address of their domain, just as the buildings in a town all share postal codes. Like a town, a domain has its own administration and systems, and the users or owners of nodes within a domain have to follow the rules set forth by the domain’s administration.

Unlike a civil administration, however, a domain administrator can actually change “reality” within her domain. A domain’s administrator can set the appearance and behavior of objects, programs, and shadows within the domain subject only to the limitations of her skills and her domain’s systems. A domain administrator can set the rules and restrictions of the domain to be immutable to everyone but herself (or another administrator), or she set up any kind of hierarchy of permissions she likes to allow users and visitors to modify local restrictions.

The variety of domains on the Grid is all but infinite. All it takes is a computer with the right hardware and software, a Grid address, and a connection to the Grid to set up one’s own domain, and many people do just that. Thus, it is difficult to categorize all of the places one can visit on the Grid. Generally (but not always), any of the types of networks described above are within single domains. Following below are just a sample of the most common and popular types of private domains.

Access Providers are huge, sprawling networks that cater to the Grid user without either to gear or the interest to set up his own domain. They provide a customizable (within certain limits) node for each subscriber, which acts as a Grid home for its owner. The services offered by access providers range from the most basic (an access point node) to personalized news and information, exclusive entertainment, to virtually any kind of service or good that can be offered over the Grid. Most access providers offer their services for free in return for subjecting subscribers to varying levels of advertising, but the more content-rich ones charge monthly fees.

AI Havens are difficult to find and extremely difficult for anyone other than AIs to access. These mysterious blue boxes, as they appear on the Grid, are the Grid homes and destinations of artificial intelligences. Rumors depict the inside of blue boxes as featureless fog banks, or swirling seas of data, or incomprehensible cityscapes of hurdling, titanic constructs.

Code Salons are the homes and the meeting places of the digerati—the tech-savvy Grid elite who spend their entire lives on the Grid. Finding and gaining access to a Code Salon is purposely difficult, an entrance exam for those who would see themselves accounted as the masters of the Grid. Within their private havens, the digerati may engage in almost any activity that can be conducted on the Grid, but gather most often to trade or show off their software, their skills, or the data they have acquired on their runs.

Content Providers include domains that offer entertainment, news, information, and other on-Grid services. The varieties of content on the Grid are mind-boggling, from simple text news reports, to interactive instructional programs, to completely realistic (or better) virtual games, simulations, and so on ad infinitum. Many content providers offer limited access to their material for free to attract customers, and then offer more complete, higher quality, or otherwise simply more products either by subscription or purchase. Content providers generally try to be very easy to find and access, their advertisements and promotions often outnumbering all other types of grid messages one receives.

Data Fringes are the dark domains where one goes to find whatever one is not supposed to have. By definition, the business that goes on the fringes is either illegal or objectionable, or both. Unsavory contacts, stolen data, restricted software, illegal and taboo media of all sorts trade virtual hands in data fringes. Such places are necessarily hard to find, requiring either grid skills or contacts to locate.

Portal Services have grown up out of the directories and search engines of previous eras. In the age of the interstellar Grid, they are even more indispensable than ever. Not only do most portal services maintain huge databanks of Grid addresses, but they also compete to offer the fastest and “smartest” tools to find what you’re looking for. Most portal providers offer their basic services for free (though often wrapped up in a layer of advertisements for sponsors), and then provide more advanced services for purchase or subscription. The very best portal services offer the paying customer access to exclusive directories, dedicated search agents, and more.