Landing Page
The landing page is also known as the "click through URL" or "destination URL".
It’s the page a user lands on when they click on a link in a search engine results page (SERP) or on an online advertisement. Landing pages are designed to be highly relevant to the advertisement or search listing and often encourage users to complete a "call to action".

Link(s)
An element on a web page that can be clicked on to cause the browser to jump to another page or another part of the current page. Links can be text or graphics and are expressed as URLs.

Link Bait
A webpage designed to attract incoming links.

Link Building 
Actively cultivating incoming links to a site by requesting links from other web sites for the purpose of increasing "link popularity" and/or PageRank.

Link Buying
Buying a link from another site for the purpose of increasing link popularity.

Link Exchange
Providing a website with a link in exchange for them providing one back to you (reciprocal linking).

Link Farm
A link farm is a group of highly interlinked websites created to subvert the link popularity algorithms of search engines.

Link Juice
Refers to the quality and weight any website can pass on to another through its pagerank and number of link “votes” which are obtained by Backlinks.

Link Partner (link exchange, reciprocal linking)
Two sites which link to each other. Search engines usually don’t see these as high value links, because of the reciprocal nature.

Link Popularity
Link popularity a measure of the value of a site based upon the number and quality of sites that link to it. A part of all major search engines’s ranking formula so the more web pages that link to you, the better your link popularity (so long as they’re quality links)

Link Spam 
Unwanted links between pages specifically set up to take advantage of link-based ranking algorithms.

Link Text (Anchor text)
Are the words in the clickable part of any link.  Link text is important because those words tell your visitors as well as search engines what the page they're about to go to is all about. Search engines give link text a lot of weight.

LSI (Latent Semantic Indexing)
Means that search engines index commonly associated groups of words in a document. In addition to recording which keywords a document contains, the method examines the document collection as a whole, to see which other documents contain some of those same words. LSI considers documents that have many words in common to be semantically close, and ones with few words in common to be semantically distant. This simple method correlates surprisingly well with how a human being, looking at content, might classify a document collection. Although the LSI algorithm doesn't understand anything about what the words mean, the patterns it notices can make it seem astonishingly intelligent.

Log File 
All accesses to a web site can be logged by the web server. Data that is usually logged includes date and time, filename accessed, user's IP address, referring web page, user's browser software and version, and cookie data.

Long Tail
Long tail refers to longer more specific search queries that are often less targeted than shorter broad queries. For example a search for “bonza” might be very broad while “bonza website site calculator” would be a long tail search. A large percentage of all searches are long tail searches.