Copyright Goodheart-Willcox Co., Inc. 138 Unit 1 Computing Fundamentals File Name Extensions The second part of the fi le name is the period. Although the fi rst part of the fi le name may contain periods as well, the last period on the right is the one Windows uses to begin the fi le name extension. The third part of the fi le name is the fi le name extension, which follows the last dot. The fi le name extension, or fi le extension, tells the Windows operating system which software to use to open the fi le. The fi le name extension indicates the format of the fi le, but does not control the format of the fi le. The software saving the fi le controls the format. Generally, when saving a fi le, the user adds the fi le name and Windows adds the correct fi le name extension. For example, if the user saves a document from Microsoft Word, the software saves the fi le as a Word document and adds the extension of .docx. It is good practice to let Windows choose the fi le name extension. Windows determines the fi le name extension based on the software program used to create the fi le. When performing a “save as” in many programs, the user can select one of many different fi le types in which to save the fi le. For example, image editing software, such as Adobe Photoshop or GIMP, may have a native fi le format, but also allows saving in several other formats, such as TIFF or JPEG. When a fi le icon is double-clicked, Windows will locate software to open the fi le, launch the software, and load the fi le. This is made possible by a feature called fi le association. File association is a process in which Windows links a fi le name extension to a software program. For example, if a fi le has an extension of .docx, double-clicking on the fi le icon causes Windows to launch Microsoft Word and load the fi le into Word. Figure 4-5 shows a few common fi le name extensions and the Windows program commonly associated with the fi le type. GS5 Computing Fundamentals 3.6.3 Key Applications 2.10.1, 3.11, 5.1.2 FYI FYI Changing the fi le name extension does not change the format of the fi le. To change the format of the fi le, it must be saved in a different format. Monkey Business Images/Shutterstock.com Computer files for schoolwork can be arranged in folders to keep everything orderly.