What is a file extension?
Also called a filename extension, it represents the suffix that appears at the end of a filename and that specifies what type of file it is. As an example, if you encounter a file called “testfile.xls”, you can tell that it is a Excel Spreadsheet, based on the “.xls” file extension. Knowing what extensions common file types use can be very helpful. There is the situation that you can not see the extension when you look at a file, that doesn't mean it's not there. It only means that your computer is set to hide them. You can choose to see them, but unless you have a really good reason to do so, you might be a little safer without.
At the same time, because there are tens of thousands of software programs available, there are also tens of thousands of file extension variations. It is handy to know the most frequent used file extensions, but it is not possible to remember all of them.
Rest assured that, even if you don’t recognize the file extension of the file that creates problems to your computer, our product is able to fix by itself any issue that your PC might have. Occasionally you may encounter a file extension that your PC doesn't recognize. At that point you just double click on the file and your computer will open up a dialog box and ask you to choose a program to open it.
If you encounter that option and you are not really confident about what you are doing, it is better to hit cancel an leave it alone than to open it. Choosing to open the file could potentially damage your computer.
Without file extensions, some operating systems will be having problems in recognizing and organizing files. This is how important these file extensions are. For simple terms, file extensions are the connectors of a specific file to an application that can render the file. They serve as the distinct identity of the file. Thus, naming a file with "test.doc" will not create a conflict with another file labeled "test.odt" even if they have similar filenames.
There are also several applications designed to execute and open files with different file extensions. A common example of these software applications are the WYSIWYG (What You See Is What You Get) applications. WYSIWYG's are used to design web pages to be uploaded to the Internet. Examples of the type of software are Dream Weaver and Microsoft Frontpage. WYSIWY's can open files with different file names. It can open *.php, *.asp, *.html, *.jsp, and several other files extension associated with the web.
The file extensions subject is quite large and can not be covered in such short space, but for a general information level, the amount of information provided should suffice.