The for loop executes a statement or a block of statements repeatedly until a specified expression evaluates to false.  there is need to specify the loop bounds( minimum or maximum).

int j = 0;

for (int i = 1; i <= 5; i++)
{
j = j + i ;
}

The foreach statement repeats a group of embedded statements for each element in an array or an object collection.you do not need to specify the loop bounds minimum or maximum.

int j = 0;

int[] tempArr = new int[] { 0, 1, 2, 3, 5, 8, 13 };
foreach (int i in tempArr )
{
j = j + i ;
}