what does this do

when i first put these forks on i completely took the blue screw out and it made the forks like super super soft, i put it back on and have been riding on them but now it seems as the blue adjuster doesn't do anything? even completely off, it feels the same as with it screwed in all the way. any help?

when i first put these forks on i completely took the blue screw out and it made the forks like super super soft, i put it back on and have been riding on them but now it seems as the blue adjuster doesn't do anything? even completely off, it feels the same as with it screwed in all the way. any help?