SEO Glossary

Inverse Document Frequency is a term used to help determine the position of a term in a vector space model.

IDF = log ( total documents in database / documents containing the term )

The number of times your search ad is served to users by search engines.

Links that point to your site from sites other than your own. Inbound links are an important asset that will improve your site’s PageRank (PR).

Most search engines allow you to see a sample of links pointing to a document by searching using the link: function. For example, using link:www.seobook.com would show pages linking to the homepage of this site (both internal links and inbound links). Due to canonical URL issues www.site.com and site.com may show different linkage data. Google typically shows a much smaller sample of linkage data than competing engines do, but Google still knows of and counts many of the links that do not show up when you use their link: function.

Collection of data used as bank to search through to find a match to a user fed query. The larger search engines have billions of documents in their catalogs.

When search engines search they search via reverse indexes by words and return results based on matching relevancy vectors. Stemming and semantic analysis allow search engines to return near matches. Index may also refer to the root of a folder on a web server.

First introduced in September 1995, Inktomi Corporation from California was a key player in the search engine market where it pioneered online search technologies. It initially provided software to ISPs (Internet Service Providers) but then went onto power other well-known web search tools such as HotBot, Looksmart, MSN, regional search engines and others.

It ultimately displaced Alta Vista when Inktomi started using a distributed network technology (instead of operating everything on one machine) that enabled them to index more than 1.3 million documents on the web at that time.

Inktomi was the first to launch a paid inclusion service that meant websites would receive regular and frequent re-indexing for a fee. It also invented a proxy cache for ISP web traffic called ‘Traffic Server’.

During its short life, Inktomi acquired many businesses including Webspective, Infoseek, eScene Networks and FastForward Networks. Once the Internet bubble had burst in 2000, many of its acquisitions were sold off due to the financial collapse of most of its customer base.

Yahoo! purchased Inktomi in 2003 which remains central to its search engine database today.

Information architecture (IA) is the art of expressing a model or concept of information used in activities that require explicit details of complex systems. Among these activities are library systems, content management Systems, Website Development, user interactions, database development, programming, technical writing, enterprise architecture, and critical system software design. Information architecture has somewhat different meanings in these different branches of IS or IT architecture. Most definitions have common qualities: a structural design of shared environments, methods of organizing and labeling websites, intranets, and online communities, and ways of bringing the principles of design and architecture to the digital landscape.

The field of science based on sorting or searching through large data sets to find relevant information.

A synonym for back links. Popularized by Yahoo!

A contract that specifies the details of your search advertising campaign, including placements options, keywords, ad creative, landing page, pricing, geo-targeting, and language options.

Link from one page on a site to another page on the same site.

It is preferential to use descriptive internal linking to make it easy for search engines to understand what your website is about. Use consistent navigational anchor text for each section of your site, emphasizing other pages within that section. Place links to relevant related pages within the content area of your site to help further show the relationship between pages and improve the usability of your website.

Sometimes called “The Net”, the Internet is a publicly accessible worldwide system of computer networks that enable people to send and receive information from other computers. The Internet uses the TCP/IP network protocols to facilitate data transmission.

There are three levels of hierarchy including backbone networks, mid-level networks and stub networks. These include commercial (.com or .co), university (.ac or .edu) and other research networks (.org, .net).

The origins of the Internet began in 1962 where a government agency called RAND was commissioned by the US Air Force to develop a military research network that could survive a nuclear attack. Packet Switching was invented as a way of sending data.

The first email program was created in 1972. The TCP/IP Protocol was developed in 1973 and by 1983 it became the core Internet protocol.

The same year of 1983 saw the development of the Domain Name System (DNS) by the University of Wisconsin. The domain name system made it easier for people to access other servers rather than having to remember the corresponding long IP numbers.

In 1992 the World Wide Web was released by CERN and the Internet Society was chartered who controls the Internet. The first graphical user interface to the WWW called ‘Mosaic for X’ was released.

By 1996, most Internet traffic was carried by independent ISPs. The Internet Society is building a new TCP/IP that will allow billions of addresses rather than the limited supply that we have today.

Microsoft’s web browser. After they beat out Netscape’s browser on the marketshare front they failed to innovate on any level for about 5 years, until Firefox forced them to.

An ad page that appears for a short period of time before the user-requested page is displayed. Also known as a transition ad, splash page, or Flash page.

Advertising space available for purchase on a website. Based on projections, inventory may be specified as number of impressions or as a share of voice. Also known as ad avail.

Portions of the web which are not easily accessible to crawlers due to search technology limitations, copyright issues, or information architecture issues.

An Internet Protocol address (IP address) is usually a numerical label assigned to each device (e.g., computer, printer) participating in a computer network that uses the Internet Protocol for communication. An IP address serves two principal functions: host or network interface identification and location addressing. Its role has been characterized as follows: “A name indicates what we seek. An address indicates where it is. A route indicates how to get there.”

ISP is an abbreviation for Internet Service Provider. An ISP provides a range of Internet related services to customers including Internet connectivity, email, website hosting, domain name registration and hosting.

Usually provided for a monthly fee, an ISP can be a commercial business, a university, a government organization, a school or any other entity that provides access to the Internet to members or subscribers.