Understanding a little about the different data formats will help you determine where you may need to use special care in transferring files. If you have used different types of computers, for example a PC and a mainframe, you may be familiar with the text format of data. Text data is just text-letters, number, and perhaps a few special characters. There is no special formatting in a text file, such as bold faced type, margin settings, or other binary codes. Text files can be moved around the Internet quite easily.
Binary files contain special codes which can be understood by the native computer.
An executable file is an example of a binary file, as are most files generated by an application. A file created by Microsoft Excel, a spreadsheet, is an example of a binary file created by an application. When moving binary files around the network, it is important that they not be altered. When using FTP to transfer files, you can specify the binary option, which assures that the file won't be altered during the transfer. Binary files cannot be sent via electronic mail unless they are encoded and then the person receiving the file must decode it.