Concatenation is two text statement to concate to a sum type
Concatenation is used + symbol to marge to statement.

Multiline string:

A Multi line String is to store multi data in String

Ex:

void main() {
  String Con_tring = '''
    This is a fun
    multi-line 
    string in 
    Dart.
  ''';
/*  
  Two ways to write
(''' is to write data''');
    (""" is to write data """");
*/
  print(Con_tring);
}