What part of a file name indictes the file type and program that created it?

Usually nothing. The file extension (the .jpeg, .exe, .png, .mov, etc.) tells what kind of file it is. Certain programs deal with certain extensions, like Word with .doc, .rtf, and .txt. Paint and Photoshop deal with .jpeg, .png, .gif, and .bmp. PowerPoint deals with .ppt, and so on. Hope this helps!