Help, sed search&replace

Plzzzz, tell me some script about this...

What does this mean ?

sed '/^ */s///'
sed '/^/s// /'

and why it's diferent ???

sed '/ */s// /g' and sed 's/ */ /g'. It's all the same ???

Thanks you very much

You have been told about the rules -
other post

Use the search function for sed - there are many posts that you can read that will assist you to understand the command (also read the man page for sed)

Check out 2nd to last post by Perderabo

and for more info...

thread closed.