What are literal characters and mask characters in WinForms MaskedEditBox control?

Literal characters and Mask characters

The format or behavior for the MaskedEditBox control is defined through its Mask. The Mask is a string that is composed of Literal Characters and Mask Characters.

Literal Characters are characters in a mask that will appear as is. Mask Characters are the placeholders for data input.

For example, a US telephone number can be represented by the Mask (###) - ### #### Extn #### In the above Mask, all the non # characters are Literal characters and the #’s are Mask characters.

Reference link: https://help.syncfusion.com/windowsforms/maskedtextbox/mask-settings