The line between tracking your browsing activity and remembering your website visits blurs in an age when cookies and similar Web technologies exist. Twitter, like many other sites, places cookies on your hard drive to help it track your site activity. However, you don’t have to worry about the company monitoring other sites you visit because there’s a limit to the information any site can gather as you navigate through cyberspace.

Cookie Misconceptions

A cookie is a tiny data file that any website can add to your computer. It often has a limited life span and it can store any information that a website owner wants to put there. Because Twitter cannot access your browser's history, it cannot view sites in your history list. However, it can remember your previous visits to Twitter by reading values that reside in cookies the site maintains on your computer. Because websites that reside on different domains cannot access each other's cookies, Twitter also cannot read a cookie that another site placed there.

Twitter's Privacy Policy

Like many other Internet companies, Twitter has a privacy policy that explains how it collects and manages information. Twitter does not require you to enable your browser’s cookies to search the site and use some other services. The privacy policy also notes that Twitter uses temporary session cookies as well as persistent cookies that remain on your hard drive until you delete them. Although you have the option to prevent your browser from accepting Twitter cookies, you'll lose some twitter functionality if you do.

Other Tracking Methods

Twitter may also use additional methods to remember your visits and track your activity within the site. Local storage, for instance, is a newer technology that stores information on your hard drive without using cookies. Twitter may also place small pixel images on a Web page or in an email message to you. This gives Twitter the ability to see when you viewed a Twitter page or opened an email from Twitter. These tracking technologies are useful because they can help you log in automatically and remember references that you set.

Twitter Tracks Clicks

In addition to using cookies to enhance your site experience, Twitter can track the way you interact with the website’s links. According to Twitter’s privacy policy, the company does this to make advertising more relevant to you, improve service and gather statistics on how many times people click specific links.

Twitter Knows Where You Came From

Even though Twitter cannot read your browser history, it can tell the URL of the Web page that sent you to Twitter. For instance, if you click a Twitter link on Facebook, Twitter can tell that Facebook sent you to Twitter. All sites have this ability, so it's nothing unusual; it happens all the time. When you interact with third-party content while you're on a Twitter Web page, that third party may use the same type of tracking technologies that Twitter uses. For instance, if you stream a video while you're on Twitter, the site that placed the video there may add a cookie to your browser.