The settings in Settings > Preferences > Advanced > Network determine how Web servers handle and monitor your Internet activities, as described below.
Cookies are pieces of information stored in files that Web servers store on your computer when you are browsing. These pieces of information allow servers to recognize your computer the next time you visit their sites. Cookies are not viruses and cannot cause direct damage to your computer system in any way, but they may record your browsing habits in intrusive manners and trace your movements across different Web sites.
Some sites use cookies to store your username, for example, so that you do not have to retype your password when you check your e-mail for a number hours after you log in. This is convenient, but it can also be a security hazard if others have access to the computer you are using.
To ensure that cookie information is kept in the browser, select Settings > Preferences > Advanced > Cookies and check "Delete new cookies when exiting Opera" and close Opera when you have finished browsing.
You may also decide that you want to disable cookies. Note, however, that you may have difficulties logging on to a significant amount of Web sites if you disable cookies. To disable cookes, select Settings > Quick Preferences and uncheck "Enable Cookies".
There are types of cookies that Opera will refuse regardless of whether you have set the browser up to handle all cookies. These are cookies set for top-level domains: domains ending in .com, .net, and .org, among others. Such cookies are considered invalid or illegal and are blocked because:
You can chose to allow all cookies to be stored on your computer, refuse all, or selectively allow certain cookies and certain types of cookies. To manage your cookie settings, select Settings > Preferences > Advanced > Cookies and select from the following options:
You can also change cookie settings for a specific site, using site preferences. Select Settings > Quick preferences > Edit site preferences.