Or if a program were to calculate a date "x" days from now, the variable "x" would be an unknown piece of data until we tell the program what "x" is. In programming, it's sometimes required to work with unknown pieces of data. That's when conditions come in handy. Conditions allow a program to perform an action based on the outcome of a previous command.3 Using this type of instruction, we could instruct a program to do one thing if the "x" variable in our latter example turned out to be 7 days, and then do different thing if the variable turned out to be 3 days. Open source software on the other hand is free. Free to download, free to install, free to use, free to modify, and free to share. Started over twenty years ago, it's a phenomenon that is gaining in both popularity and exposure. In its first conception, open source gave birth to the World Wide Web as we know it today. As a result, you can find tons of games, databases, GPA systems, weather reporting programs, and even small encyclopedias on these things - each accessible not at the click of a mouse - but at a few presses of a free thumb. Of course a mini keyboard is available for the text-messaging fan or for the poor fellow who can't seem to get away from the office. If you find that you can't type information into one of these, you can effectively resolve the issue with a technician by calling it an input box, rather than a "white rectangle," or "place to put in text." Button - buttons perform a command after a user clicks them with a mouse. Problems occur when the text of a button is grayed out or if it doesn't appear to sink into the screen when clicked. jpg format (the latter two being the most commonly format used for Internet eye candy). Media Player. Real Player and QuickTime are the first programs we think of when we think about multimedia. But Windows Media Player, also free and pre-installed, does a fine job at transmitting Internet-bound sound and video. Customizing Your Computer with Preferences Making Your Computer Work with You - Not Against You Although you did not design or build your computer, you can turn it into a device that responds to your way of using it as if you were its original engineer or programmer. This is because the computer is a mere platform - a blank canvas, if you will - waiting for you to direct its operation or paint the picture of the perfect machine.