Insertion Sort is one of the simplest, but less effective, sorting algorithms . It works very similar to the way (us humans) sort a hard of playing cards:
1. At first none of our cards are sorted . So we start with an “empty” space in our hand were we are going to insert cards one at a time . 
2. We take a card from our hand and we put it in the “special place” were we planned to keep our cards sorted . We do this for every card in our initial hand, until we finish them off . 
3. Finding the right position for the insertion is not hard . At this point we can apply two tactics :

In our case that “special place” were we are going to insert cards one at a time, is not an additional array, but the array itself . We know for sure that an array of size 1 is always sorted, so we consider that first sorted subarray, is the block composed by the first element .
For example, we want to sort the following array (with bold, are the elements already sorted):
8  0  3  11  5  1  14  10  1  1  2  Array is unsorted . 
8  0  3  11  5  1  14  10  1  1  2  The first sorted block is {8} . 
0  8  3  11  5  1  14  10  1  1  2  We compare {0} with {8} we move {0} at the new position, we shift {8} . 
0  3  8  11  5  1  14  10  1  1  2  We compare {3} with {8}, {0}, we move {3} at the new position, we shift {8} . 
0  3  8  11  5  1  14  10  1  1  2  We compare {11} with {8}, {11} remains at the same position . 
0  3  5  8  11  1  14  10  1  1  2  We compare {5} with {11}, {8} and {3}, we move {5} at the new position, we shift {8}, {11} . 
1  0  3  5  8  11  14  10  1  1  2  We compare {1} with {11}, {8}, …, {0}, we move {1} at the new position, we shift {0}, {3}, … {11} . 
1  0  3  5  8  11  14  10  1  1  2  We compare {14} with {11}, we move {11} at the new position . 
1  0  3  5  8  10  11  14  1  1  2  We compare {10} with {14}, {11}, {8}, we move {10} at the new position, we shift {11}, {14}. 
1  0  1  3  5  8  10  11  14  1  2  We compare {1} with {14}, {11}, …, {0}, we move {1} at the new position, we shift {3}, {5}, …, {14} . 
1  0  1  1  3  5  8  10  11  14  2  We compare {1} with {14}, {11}, …, {1}, we move {1} at the new position, we shift {3}, {5}, …, {14} . 
2  1  0  1  1  3  5  8  10  11  14  We compare {2} with {14}, {11}, …, {1}, we move {2} at the new position, we shift {1}, {0}, …, {14} . 
The pseudocode for the algorithm can be easily written as follows:
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FUNCTION SORT(A, length) // The array is 0indexed FOR i:=1 TO length DO key := A[i] j := i  1 // COMPARE WHILE j >= 0 AND A[j] > key DO // SHIFT A[j+1] := A[j] j := j  1 // MOVE A[j+1] = key 
2. Algorithm Implemenation in Java
The Java implementation of the algorithm is pretty straightforward (follow the comments): Read More