Blunt/blunt Scissor has blunt tip ends which is the most commonly used as it is difficult to cause unwanted damage with blunt tips, i.e. when removing a dressing.
Blunt/sharp Scissor has one blunt tipped blade and a sharp tipped blade and so is useful where a sharp point may be needed but retains the blunt tip to offer protection to the surrounding area, i.e. use the blunt tip towards the patient when removing a dressing.
Sharp/sharp Scissors are the least commonly used scissors but are preferred by some care must be taken with the sharp points to avoid iatrogenic damage.