The default is that value of a parameter that is used if no value is chosen.

Examples:

In a text processing software, the user may choose font sizes [parameter] such as 10, 12 or 14 point cicero [value] and line heights [parameter] such as simple, 1.5-fold, 2-fold [value]. If he choses none of these values, he can write nevertheless. Nor does he then write without font size or without line height. Instead he writes with the default values of these parameters, which in this example are values set by the manufacturer of the software.

Speech sounds differ on the parameter of nasality, on which one may choose the values 'oral' and 'nasal'. If one does not choose, the sounds are (not neither oral nor nasal, but) oral. This holds, e.g., for English vowels.