Cookies are files sent by web servers to web browsers, and stored by the web browsers.
The information is then sent back to the server each time the browser requests a page from the server. This enables a web server to identify and track web browsers.
There are two main kinds of cookies: session cookies and persistent cookies. Session cookies are deleted from your computer when you close your browser, whereas persistent cookies remain stored on your computer until deleted, or until they reach their expiry date.
CompChem publishes Google Adsense interest-based advertisements on this website. These are tailored by Google to reflect your interests. To determine your interests, Google will track your behaviour across the web using cookies. You can view, delete or add interest categories associated with your browser using Google's Ads Preference Manager, available at: http://www.google.com/ads/preferences/. You can opt-out of the Adsense partner network cookie at: http://www.google.com/privacy_ads.html. However, this opt-out mechanism uses a cookie, and if you clear the cookies from your browser your opt-out will not be maintained. To ensure that an opt-out is maintained in respect of a particular browser, you should use the Google browser plug-in available at: http://www.google.com/ads/preferences/plugin.
Most browsers allow you to refuse to accept cookies.
In Internet Explorer, you can refuse all cookies by clicking “Tools”, “Internet Options”, “Privacy”, and selecting “Block all cookies” using the sliding selector.
In Firefox, you can adjust your cookies settings by clicking “Tools”, “Options” and “Privacy”.
Blocking cookies will have a negative impact upon the usability of some websites.