Please do not logout with processes suspended, use fg to return to them and exit them normally. Ctrl-D is used to mark the end of a file from the keyboard. If Ctrl-D is hit at the command prompt, you will be logged out. So, be careful when using it. The following table shows a list of DOS commands and their UNIX equivalent.
Flags are single letters that modify the program's behavior.
Sometimes flags require their own arguments as well. Often arguments are file names. The ls command displays file information. It takes a list of files as its argument. This list may be explicit or generated by wildcards.