man grep:

   -Z, --null
      Output a zero byte (the ASCII NUL character) instead  of  the  character  that  normally
      follows  a  file  name.   For example, grep -lZ outputs a zero byte after each file name
      instead of the usual newline.  This option makes the output  unambiguous,  even  in  the
      presence  of file names containing unusual characters like newlines.  This option can be
      used with commands like find -print0,  perl  -0,  sort  -z,  and  xargs  -0  to  process
      arbitrary file names, even those that contain newline characters.

   -z, --null-data
      Treat the input as a set of lines, each  terminated  by  a  zero  byte  (the  ASCII  NUL
      character)  instead of a newline.  Like the -Z or --null option, this option can be used
      with commands like sort -z to process arbitrary file names.

man xargs:

   --null
   -0     Input  items are terminated by a null character instead of by whitespace, and the quotes
      and backslash are not special (every character is taken literally).  Disables the end of
      file  string,  which  is treated like any other argument.  Useful when input items might
      contain white space, quote marks, or backslashes.  The GNU find -print0 option  produces
      input suitable for this mode.

man find:

   -print0
      True;  print  the  full  file  name on the standard output, followed by a null character
      (instead of the newline character that -print uses).  This allows file names  that  con‐
      tain newlines or other types of white space to be correctly interpreted by programs that
      process the find output.  This option corresponds to the -0 option of xargs.