for loop

for VARIABLE in 1 2 3 4 .. N
do
    # command 1
    # command 2
done

Bash version 3.0+ supports built-in for setting up ranges:

for i in {1..5}
do
    # echo $i
done

Bash version 4.0+ supports for setting up a step value using {START..END..INCREMENT}

#!/bin/bash
echo "Bash version ${BASH_VERSION}"
for i in {0..10..2}
  do
      # echo $i
  done