Programs frequently need to deal with many instances of something: for example consider a program that how many people attended each robotics meeting.  You could create a variable for each robotics meeting:

{{{
  int meeting1_attendees;
  int meeting2_attendees;
  int meeting3_attendees;
  int meeting4_attendees;
}}}
But that's awkward (especially if you met 50 times during the season).  Fortunately, Java offers a type of variable called an ''array''.

The following declares a variable that stores 50 integers:

{{{
   int meeting_attendees[]=new int[50];
}}}
To print the attendees at meeting 3 you would use:

{{{
   System.out.println("Meeting 3 attendees:"+meeting_attendees[2]);
}}}
Notice that the 3rd element of the array is at index 2 since the first element is at index 0.

Arrays are particularly powerful when you combine them with loops; consider the following:

{{{
   for (int mtg=0; mtg<50; mtg++) {
       System.out.println("Meeting "+mtg+" attendees:"+meeting_attendees[mtg]);
   }
}}}
Loops and arrays give you a concise way to programmatically process large collections of data.

=== Extra credit ===
 * Read more about [https://www.geeksforgeeks.org/arrays-in-java/ Java arrays]