Use to copy the file currently displayed in the active view
window from memory to disk. The file remains in memory.
 
With Save As you can save to a different file than the one
you loaded your program from, preserving the original
version.
 
Tip: Save is faster than Save As, but Save always
     overwrites the disk file from which the current file
     was loaded. Use Save All when you are working on
     multiple-module programs.