Zips and Rars - Opening Archived Files
When a file arrives on your computer, you expect it to open properly once you click on it. Not only that, you expect the correct program to open as well. For example, if a family member sends you a group photos, you expect the images to open, usually in a viewing program of some kind when you click on them. But what if the photos are stored in an archive? Now what?
Before discussing how to open archived files, let's look at why files are archived in the first place using photos as an example. Today's digital cameras are capable of creating high resolution photographs. It's not unusual for a single photo to be 3.5 megabytes or higher in size. Now, imagine if a family member wanted to send you a group of 10 photos, each 3.5 megabytes in size. That single email would be 35 megabytes, well over the file transfer limit of many ISPs. By grouping the photos into a compressed archive, not only would just one file be transferred, the files within the archive will be compressed bringing the overall file size down to a more manageable size. Compressing and archiving photos is done with programs such as WinZip, WinRAR, and BitZipper.
While the user who has compressed the files has good intentions in mind, not all computers are equipped to open the compressed archives. Some users are aware that you may not be able to unzip the file and take advantage of self-extracting features. When this is the case, the file will be an executable file that automatically unzips when you click on it. When this isn't the case and your computer doesn't automatically unzip the files, you may be left scratching your head wondering what to do next. The first step is to identify the file extension so that you can then determine which program is needed to extract the files. For example, if the file is named "familyphotos.zip," the.zip file extension tells you that it is a.zip file, one of the more common compressed archive file types. In this case, downloading WinZip will do the trick.
Many file compression programs are capable of opening compressed files created by other programs. Not only can WinZip open.zip files, it can also open.rar,.tar,.zipx,.7z,.bz2,.gzip,.tz,.taz, and many others. The same is true of programs like WinRAR and 7-Zip. As you research the file extension, you'll likely find several programs capable of opening the file. Once you download and install the utility, your computer will know what to do with the compressed file and prompt you to "extract" the files.
By knowing the file extension of the compressed file, you have a valuable clue which can lead you to finding the right decompression utility for opening the archive. However, if you decompress a compressed archive, keep in mind that there's no guarantee that your computer will be equipped to open the archive's contents. In our example of familyphotos.zip, the.zip file contains photos which are most likely in the universal.jpeg format so that shouldn't pose a problem. But what if the.zip file contains Excel spreadsheets in the.xlsx format and you do not own Excel or your version is not capable of opening this format? You're back at square one, researching the file extension to figure out how to open it. With this in mind, it's not a bad idea to find a good file extension library on the Internet and bookmark it for future use.
Sources: http://www.winrar.com http://ezinearticles.com/?Zips-and-Rars---Opening-Archived-Files&id=3503526