Opera Help and Support

The settings in Preferences > Advanced > Content allow you to set up external applications that Opera can use to enhance your browsing experience.
Plug-ins
Plug-ins are external applications that Opera can use to display images and video clips, show files, or play sounds that the browser is not able to handle by itself. Some of the most popular plug-ins are Macromedia Flash, QuickTime, and Adobe Acrobat.
Plug-ins are essentially separate applications. Therefore, Opera's various security settings will have no effect on how plug-ins work. It's a good idea to do your homework before installing new plug-ins. For example, a plug-in like RealPlayer can make use of cookies, and Opera's cookie settings will have no effect on these.
To see a list of installed plug-ins, open the built-in plug-in overview. Note that Opera for Linux has a separate preference window for installing and locating plug-ins.
Please keep in mind that any plug-in you add is an application installed on your computer. As always, protect your computer and download software only from reputable sources.
JavaScript
JavaScript (or actually ECMAScript) is a means of embedding executable content in Web pages. It is used for everything from making image links change when your mouse hovers over them, to receiving and sending cookies.
These scripts are completely safe most of the time, but they have been used for malicious purposes. JavaScript should not be able to access applications and information outside the Web page it resides on, but if you still fear JavaScript abuse, you can choose to disable it. You can also put some limits on what Opera should let the script do, e.g., resize or move windows, by clicking "JavaScript options". And you can choose to have the JavaScript console displayed should there be an error.
If you completely disable JavaScript, however, some sites may report errors, fail to display vital content such as menus or even shut you out. Remember that JavaScript is easily toggled on and off by way of Opera's "Quick preferences", that is displayed by pressing F12.
Java
Java is considered to be very secure today. If Java is installed and enabled in Opera, your system is unlikely to face security problems relating to Java. However, if you are still concerned that Java might be a security risk, disable it here. Enabling Java is also a Quick preferences option.
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