Hi,
Ip Ranges are classified in 5 five classes : Class A, Class B, Class C, Class D and Class E. In which only A, B and C are commonly used.
An IP have 4 parts AAA.BBB.CCC.xxx - the first part is called A-class, the second part B-class and the third part C-class and IP under the last part will be in the C-class. So for example:
111.222.333.1 and 111.222.333.2 are in the same C-class but
111.222.333.1 and 111.222.334.1 is in two different C-classes
Effect on
SEO orientation :
In
SEO orientation webmasters build links from a variety of networks. Which have some consiquences in the past search engines have applied penalties to entire IP ranges consider it as a spamming activity. If the links have common IP addresses many of them do not improve on relevancy score. So most of the webmasters use unique C class ips.