Scanner doesn't read whole sentence - difference between next() and nextLine() of scanner class

Question

I\'m writing a program which allows the user to input his data then outputs it. Its 3/4 correct but when it arrives at outputting the address it only prints a word lets say

Answer 1

import java.util.Scanner;

public class Solution {

    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        String s = scan.next();
        s += scan.nextLine();
        System.out.println("String: " + s);

    }
}