In its simplest form supported by all versions of bash, case statement executes the case that matches the pattern. ;; operator breaks after the first match, if any.

#!/bin/bash

var=1
case $var in
1)
  echo "Antartica"
 ;;
2)
  echo "Brazil"
 ;;
3)
  echo "Cat"
 ;;
esac

Outputs:

Antartica

Since bash 4.0, a new operator ;& was introduced which provides fall through (opens new window) mechanism.

#!/bin/bash

var=1
case $var in
1)
  echo "Antartica"
  ;&
2)
  echo "Brazil"
  ;&
3)
  echo "Cat"
  ;&
esac

Outputs:

Antartica
Brazil
Cat

Since Bash 4.0, another operator ;;& was introduced which also provides fall through (opens new window) only if the patterns in subsequent case statement(s), if any, match.

#!/bin/bash

var=abc
case $var in
a*)
  echo "Antartica"
  ;;&
xyz)
  echo "Brazil"
  ;;&
*b*)
  echo "Cat"
  ;;&
esac

Outputs:

Antartica
Cat

In the below example, the abc matches both first and third case but not the second case. So, second case is not executed.