Classless Inter-Domain Routing
An IP address is interpreted as composed of two parts: a network-identifying prefix followed by a host identifier within that network. In the previous classful network architecture, IP address allocations were based on the bit boundaries of the four octets of an IP address. An address was considered to be the combination of an 8, 16, or 24-bit network prefix along with a 24, 16, or 8-bit host identifier respectively. Thus, the smallest allocation and routing block contained only 256 addresses—too small for most enterprises, and the next larger block contained addresses—too large to be used efficiently even by large organizations. This led to inefficiencies in address use as well as inefficiencies in routing, because it required a large number of allocated class-C networks with individual route announcements, being geographically dispersed with little opportunity for route aggregation.
Home page
In the early days of the World Wide Web in the first half of the 1990s, an important part of web pages belonged to students or teachers with a UNIX account in their university. System administrators of such systems installed an HTTP server pointing its root directory to the directory containing the users accounts. On UNIX, the base directory of an account is called "home", and the codice_1 environment variable contains its path (for example codice_2). The URL of the home page usually has the format codice_3. Thus the term home page appeared and then spread to its current usage.