A parameter may refer to any of the following:
1. In reference to a URL, a parameter is any data appearing after a question mark (?), which sends additional information to the sever. Multiple parameters are separated by an ampersand (&). For full details about a URL and its parameters, see our URL guide.
2. Sometimes abbreviated as parm, with a command, a parameter refers to an unknown data value capable of being set through a command by the user. For example, the command FDISK /CMBR <DISK> requires that the user specify the "DISK" parameter. In this example, a parameter allows you to chose what disk drive you want to use when recreating the master boot record.
In the above example, /CMBR is a command switch and should not be confused with a parameter. Command switches often begin with either a forward slash ( / ) or a dash ( - ) depending on the command line.