Initially the sites were mainframe computers with perhaps a hundred users per machine. Today, we have a range of computers connected, some mainframes and many workstations with anywhere from a dozen users to a single individual. These connections to the backbone generally fall into one of two categories. So-called full Internet connectivity implies that the connection is transparent to the user. If you have the right hardware, software and permissions, you can connect your computer on one network to a computer on the other network and use any of the Internet tools, such as browsing on servers for text or graphics information, transferring files or using a library catalog program.
Some networks only have a limited connection to the Internet.
For example, the most limited connection is the transferring of electronic mail messages by collecting messages on a magnetic tape and physically transferring this tape to a computer on another network. Some networks, while they have a full physical connection, choose to offer limited services. This network served some 2,000 nodes in about 50 countries. These sysops developed the practice of passing groups of personal messages and files to their closest neighbors over phone lines in the middle of the night when traffic and rates were low. Burt Juda at IEEE maintains one of these Fidonet connections.