The "right click" (referring to a computer mouse) is the less formal name of the contextual click. Most modern operating systems and/or mouse drivers allow you to change the "handedness" of your mouse (though for consistency reasons I don't know many left-handed people that do). On most platforms (Windows, Linux, and Macintoshes with two button mice attached to them), the second mouse button accomplishes this task. On older (and default) Macintosh systems, with one-button mice, holding down control while clicking brings up contextual menu choices.

Typically, this alternate click is used to bring up a series of applicable and commonly used options (actions) with regard to the currently pointed-to object. However, the usability of the right-click has been shown to be quite dubious. Many novice users do not take advantage of this button (and thus it was left out of the Macintosh UI design for simplicity). Since the result of this action varies from situation to situation, it has been shown to confuse less experienced users. The right click simply does not work, as an option.

You'll notice that in a major application where usability is well tested (such as Microsoft Office), all tasks available through a right-click are found in the menus. This is because the discoverability of a feature located in only contextual menus is low. When looking for the function to accomplish a task, users have been commonly shown to do everything but actually click on the object. In many temp-agency tests, right-click options are forbidden from being correct answers in proficiency examinations; many professional environments work in keystroke shortcut patterns and navigation of the menus. There is a balance for usability between the convenience for mid-range to power users, and the discoverability for the large base of novices. Office's two latest versions (for the Macintosh and the PC) have solved this in two different ways, each appropirate for their task.

Macintosh Office 2001 has the new Formatting Palette, a Mac-only feature that gives you a toolbar that shows you what applies to the current selected object onscreen. The large floating (as compared to docked) toolbar is similar to others in very Mac-like programs, such as those employed in Adobe Photoshop. It allows users to escape the right-click by seeing what is available when an object is highlighted. This is very important, since many Mac users still have one-button systems. Though the options are still there, Office: Mac presents many alternatives for many ranges of users.

In Office XP, there is a concept of On-Object UI. Whenever an object is selected rather than requiring the user to perform a right-click, it presents them the options of what to do as a new UI on the object itself (without further interaction with the users). This active presentation allows even Windows users, the ones supposedly familiar with the right click, the ability to discover alternatives.

The right click is a tool in a programmer’s arsenal to expose features to the user in a clean and intuitive manner. It has been around for some time (the days of Windows 3.1 and earlier on other systems), and has seen eventual "native" support in MacOS X, according to Steve Jobs (though the default USB mouse drivers from 8.6+ supported contextual click). Users have never gotten used to the concept of this mouse action, and rely more heavily on such mouse procedures as drag and drop, double click, and of course, single click.

In recent years we are beginning to see mice with many more buttons: Microsoft, a place that is mildly agressive in their UI choices (but careful since BOB), produces an optical mouse now with two top buttons, the wheel, and two buttons on the side. Above the wheel, these are not used in any meaningfully way in the UI, because any dependency on their optional features would be ridiculous.

In the end, the right-click is nice to have around, but is oftentimes outweighed by users who are more keyboard-heavy, or ones who understand tasks as a series of clicks, and not logical relations between actions. The "more information about the current object" is great for people who are curious as to how to interact with something, but is not a wonderful solution in and of itself. More “active” and “intelligentUI designs need to be sought out for the human-computer interaction of the future.