If i delete photos off my icloud will they be deleted off my phone aswell?

I am trying to create more space in my icloud and I dont want to pay for more space as i am young and dont have alot of money.

i had an iphone 5 and i backed up everything on my icould and then got an iphone 6s, i restored all my data from my 5 and i now want to back up my 6s but i cant because the backup of the 5 takes up too much space, if i "delete the back up" of my iphone 5 will all the pictures and data i have downloaded from my icloud onto my 6s get deleted?