Answer to Question 1
Cookies can be placed on the client computer by the Web server site, in which case they are called first-party cookies, or they can be placed by a different Web site, in which case they are called third-party cookies. A third-party cookie originates on a Web site other than the site being visited. These third-party Web sites usually provide advertising or other content that appears on the Web site being viewed. The third-party Web site providing the advertising is often interested in tracking responses to their ads by visitors who have already seen the ads on other sites. If the advertising Web site places its ads on a large number of Web sites, it can use persistent third-party cookies to track visitors from one site to another.
Answer to Question 2
There are two ways of categorizing cookies: by time duration and by source. The two kinds of time-duration cookie categories include session cookies, which exist until the Web client ends the connection (or session), and persistent cookies, which remain on the client computer indefinitely. Electronic commerce sites use both kinds of cookies. For example, a session cookie might contain information about a particular shopping visit and a persistent cookie might contain login information that can help the Web site recognize visitors when they return to the site on subsequent visits. Each time a browser moves to a different part of a merchants Web site, the merchants Web server asks the visitors computer to send back any cookies that the Web server stored previously on the visitors computer.
Differences in the number and location of flagella.
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This map shows the percentage of Protestants by state in Germany. When compared to the previous map
An outline of the mechanism of protein splicing
Outline of Meiosis II