Command mode is when a user says words linked to commands, which are then interpreted and executed. You might use command mode to navigate menus in applications or activate macros. This is how voice recognition is used in Auto PC and the voice applications for phone systems. Each word is recognized independently and processed by the recognition software, then passed to the operating system or active application as a command, keystroke or predetermined set of commands. In dictation mode, the computer transcribes what you say into a word processing document, e-mail or other application, adding appropriate punctuation and spelling the words based on context.
Dictation is a more difficult computing function than command mode.
That's where most voice recognition software runs into trouble. Although great strides have been made in improving the recognition skills of desktop PC voice tools, those advances have increased the overall accuracy of voice recognition only slightly. Unless you have a very good reason to use voice recognition for dictation, you're better off not doing it, unless you don't mind typing in the corrections later. Most voice recognition software does best at command mode, handling well-worn sets of verbal commands. Fortunately, this is the type of voice recognition that gets the most mileage in most voice recognition applications.