A single graphic image, generally in a GIF or JPEG format, containing multiple hyperlinks .
Inbound link
A link from an external domain to a web site, bringing traffic to that site. Inbound links are used to measure link popularity.
Index
A searchable database of words pointing to documents created by search engine software.
Indexer
The part of the search engine that processes and places spidered, or crawled, web documents into a database. The indexer typically processes a document by removing all tags, storing links in a queue, removing filter words, looking for stop words, and storing the document in a searchable database.
Information page
A static web page that contains quality content about a specific topic. The page is written for a site's target audience but formatted for easy search engine spidering.
Invisible web
Web sites or pages that search engine spiders cannot or will not crawl because the content is locked up in a database.
IP address
A unique number that identifies every computer on the Internet. Currently, an IP address consists of four, 32-bit numbers (from 0 to 255) separated by periods, such as 255.195.12.13.
IP delivery
A type of cloaking technique where customized content is delivered to a site visitor based on the visitor's IP address. Because search engines have unique IP addresses, content delivered to the search engines is not the same content delivered to site visitors .
IP spoofing
The act of sending messages to a computer using an IP address from a trusted source to gain unauthorized access to that computer. IP spoofing is illegal in many countries .
ISP
Abbreviation for Internet service provider. An ISP is a company that provides access to the Internet.
