Effect of z-index value to positioned elements

This is relatively positioned block, with z-index:10

This is absolutely positioned block, with z-index:30

Content between the RP blocks... Content between the RP blocks... Content between the RP blocks... Content between the RP blocks...

This is relatively positioned block, with z-index:12

This is absolutely positioned block, with z-index:25

Content after the second RP block... Content after the second RP block... Content after the second RP block... Content after the second RP block...