CGI: cgi stands for Common Gateway Interface. Perl, C, and PHP are the programming languages of Common Gateway Interface. It is a standard protocol for interfacing the external application server with information server commonly a web server.

CGI-BIN: In any server it is most common name of a directory that is seen in every web server. It contains CGI files which are under heavy access of the users. Purpose of the CGI-BIN is to hold the executable files.

Citation: A citation is a reference to article or web page and generally known as HREF link to a location of website or web pages.

Click Through: If the visitors come to the advertiser's Website by clicking on a web advertisement, this entire process is generally called as Click Through.

Click Tracking: Click tracking means counting clicks of a website means how many visitors came to the website by using Java technology.

Client: Client is a program which sends a request to a serverCloaking: Cloaking means the technique of black hat search engine optimization (SEO), in black hat seo the content showed to the search engine crawlers is different and the visitors will see the different content in the same website.

Combined Log file: Combined Log file contains data in common log file and information in referrer and user agent fields.

Clustering: Search engines cluster pages in same website to keep one site from dominating top results.

Cold Fusion: Cold Fusion Is an Allaire database program which uses cf or cfm as extension, which also used by cloaking programs.

Common Log File: Developed by NCSA in which the data is limited by it’s lack of referrer and user agent information.

Comment Tag: Comment Tag is used in relation to search engines for indexing, which marks html code rather displaying it.

Conversion Rate: Conversion Rate describes the relationship between visitors to sales or actions. From 100 visitors 1 visitor purchases website products, we can say the conversion rate of 1 to 100.

Counter: counter is a calculator that keeps the records of the number of times clicks or page views to a web site.

CPA: CPA means cost per action. By clicking web advertiser’s ads, the visitor purchases the products or services from the advertiser’s website the website publisher will be paid by the advertisers. This total process is called cost per action.

CPC: CPC stands for Cost per Click, Cost per Click measures the cost on a per click basis not based on click thorough.

CPL: CPL means Cost per lead. The publisher website drives the Visitors or traffic to the advertiser’s website, if any visitor registers their name with advertiser’s website for the purpose of buying products or services. By providing leads to the advertisers the publisher will get amount according to their agreement.

CPM: cpm means Cost per Thousand (M=1000). If visitors view the ads of the advertisers in publishers webpage at 1000 times the advertisers pays the amount to the publishers. CPM generally known as cost per impressions (1,000).

Crawler: Also known as a web crawler, spiders, robots. Crawler is a program that gathers the information from the Web and sites the data in their database. Search engines use the crawler to gather the information.

Cross Linking: Group of websites or domains those sites are owned by the same company or individuals, those websites linked to each other for the purpose of getting traffic and page rank with search engines. This is often called as cross linking.

CSS Cascading Style Sheets: CSS is an external file and used for adding styles to web pages of the website. This helps in opening the page quickly on the web.

CTR: CTR means Click through Rate. The number of times (in percentage) that visitors click on the advertiser’s ad. The page is viewed 100 times and a visitor clicks on ad once, then the CTR is 1%.

Cyber Squatting: Reserving or trade marking an Internet domain name or website domain name for the purpose of selling it later to a company that wants to use it.