What is the difference between "white-space" and "space" (the result of pressing the space key) in the filters under "Search"?
Space = ASCII space (character code: 0x20 / 32)
The following characters are treated as white-space in Everything:
TAB '\t' (0x09 / 9)
NEWLINE '\n' (0x0A / 10)
VERTICAL TAB '\v' (0x0B / 11)
CARRIAGE RETURN '\r' (0x0D / 13)
SPACE ' ' (0x20 / 32)
NO-BREAK SPACE ' ' (0x00a0)
OGHAM SPACE MARK ' ' (0x1680)
EN QUAD ' ' (0x2000)
EM QUAD ' ' (0x2001)
EN SPACE ' ' (0x2002)
EM SPACE ' ' (0x2003)
THREE-PER-EM SPACE ' ' (0x2004)
FOUR-PER-EM SPACE ' ' (0x2005)
SIX-PER-EM SPACE ' ' (0x2006)
FIGURE SPACE ' ' (0x2007)
PUNCTUATION SPACE ' ' (0x2008)
THIN SPACE ' ' (0x2009)
HAIR SPACE ' ' (0x200a)
LINE SEPARATOR '
' (0x2028)
PARAGRAPH SEPARATOR '
' (0x2029)
NARROW NO-BREAK SPACE ' ' (0x202f)
MEDIUM MATHEMATICAL SPACE ' ' (0x205f)
IDEOGRAPHIC SPACE ' ' (0x3000)