Categorizing Networks by Network Operating System
Networks are often categorized by their operating systems. The five
main types are listed below.
While Linux can be considered a variant of UNIX, it really has its own following. There are other network operating systems, but these are the most common. Some networks end up being a hybrid of these operating systems and more will be said about this in the following paragraphs.
Windows Networks. Windows server based networks are called domains. A domain controller holds the read/write copy of the SAM - security account manager. There can be more than one domain controller on a network, but this can get complicated very easily. Windows 2000 is based on something called Active Directory in which a copy of each is held on each domain controller. Each of these copies can read/write to the directory database.
NetWare Networks. Novell's NetWare provides logon security and functions as a file and print server. Windows networks can access NetWare servers if they have the appropriate client software installed. NetWare versions 4.x and 5.x provide directory services through NDS - NetWare Directory Services. The NDS is a hierarchical database that likely inspired Microsoft's implementation of Active Directory.
UNIX Networks. UNIX was the operating system used on ARPAnet, the precursor of the Internet. UNIX was developed at Bell Labs in 1969 and has a fairly large variety of versions due to its open source nature. UNIX is powerful, text based and relatively difficult to learn for many users. Others find it clean and direct.
Linux Networks. One might say that Linux was developed in order to get a UNIX like operating system on desktops and networks. It generally is much more accessible to the general populace interested in operating systems due to cost, availability, ease of implementation and size.
Hybrid Networks. Most medium or larger networks are going to end up being hybrid networks. Maybe the art department is running Macs, the organizations core administration is running Windows, and the engineers are running UNIX.
There exist a variety of interoperability software packages such as the following.