I recently received an e-mail with a picture from an 80-year-old relative. I am very proud that she can learn to use a computer at her age. Unfortunately, I cannot read the file and I am reluctant to ask her to go through the process again. I know it is a picture, but the file ends with the extension 'php'. I thought that was used for programming or something. I have been unable to read the file or view the picture. She said she scanned it and sent it. Does that help?
TrevorMid-Levels
File extensions are wonderful things when they work. With the exception of Mac OS 9 and below, however, most of the time they do not behave properly. With the original MS-Dos operating system, file extensions were restricted to three letters and they had strict meanings. Anything that ended in 'com' or 'exe' was 'an executable' or what we today would call an application or program. It gave you a false sense of control, however, because the extension had no real influence or meaning. It was meant as a hint to help you remember what something was supposed to be.
When Apple brought out the Macintosh in 1984, it changed things quite radically. It allowed for two 'forks' in a file, one for the data and the other for what it called the 'resource'. The resource fork actually tied the file to a particular application and you could double-click on it and it would launch the correct application. With DOS and later Windows, this was not possible.
Unfortunately, Apple's great idea had to be abandoned because it was non standard. With its new OS, Mac OS X, the two forks have disappeared. Both the latest Windows OS and the Mac OS will handle file extensions reasonably well if it is a file you have created on your own machine. If it is something you got from the Web or, as in this case, something sent to you, things get more problematical. Both systems are likely to bring up a menu and ask you what application should open the file. This is not a problem if you know exactly what the file is. If you do not, then you may have to make a guess.