Trim end of line whitespace - When enabled, end of line whitespace is deleted.
Compact whitespace groups - When enabled, consecutive whitespace characters are trimmed to a single space character. It does not affect indentation, that is the whitespace at the beginning of a line is not affected by this option.
Tabs and Spaces - Lines are indented using tabs or spaces depending on the preferences configured in
Window > Preferences > General > Editors > Text Editors:
Insert spaces for tabs option is enabled, indentation will use space characters, otherwise tabs will be used.
Displayed tab width option controls the size of a tab in spaces.