Confused by absolute positioning options

[jjmclell]

I'm trying to use absolute positioning to place some square shapes in specific spots on a page and I'm finding it confusing. What is the difference between positioning something 5" to the right of the margin vs. 5" to the right of the left margin? Depending on which option I choose, I get different results.

Also, what does it mean to position something to the right of the inside margin or the outside margin?