If you are unfamiliar with file extension, this is the characters found in the end of the file that serves as your guide when it comes to the program that you need to use when you want open it. For example if someone sends you a file extension avi, it means that you need to open audio video file. Another is file extension mdf where you will need a software program called Alcohol 120%. There are lots of file extensions out there and it is very important if you can find a reliable website that could serve as your guide.
What if you receive a file with a file extension unknown? There are ways to which you can identify the file. First is by looking at properties of the dialog box. You can find in there letter code that corresponding to your file. Search it from the internet to know what kind is it. You can also download a shareware program that could help you in identifying the program associated with your file. If you still can’t find it, you may want to ask the sender of what kind of file it is.
Remember to be careful when opening a file because it may contain virus that can harm your computer.