In a personal computer application, to export is to convert a file into another format than the one it is currently in. Once the file is exported to the desired format (specified in its file name suffix), it can be opened and worked on by an application that recognizes and uses this format. Adobe Photoshop and other programs use this term. Other applications such as Word let you export a file by simply specifying the appropriate file name suffix when you use the "Save as" selection.
A file that has not been exported to a desired file format can be import ed by an application program and then opened and used.