The graph of [4,10] looks like this:

---------●=======================================================●------
-6  -5  -4  -3  -2  -1   0   1   2   3   4   5   6   7   8   9  10 11 12

because it has brackets on the end and so it includes both its end points.

If the interval had been (4,10) it would not have included its endpoints 
and have had open circles at the end points:

---------o=======================================================o------
-6  -5  -4  -3  -2  -1   0   1   2   3   4   5   6   7   8   9  10 11 12

If the interval had been [4,10) it would have included the left endpoint 
and not have included the right end point:

---------●=======================================================o------
-6  -5  -4  -3  -2  -1   0   1   2   3   4   5   6   7   8   9  10 11 12

If the interval had been (4,10] it would have included the right endpoint 
and not have included the left end point:

---------o=======================================================●------
-6  -5  -4  -3  -2  -1   0   1   2   3   4   5   6   7   8   9  10 11 12

Edwin