The degree of loft on a wedge differentiates it from other wedges. Pitching wedges have a loft between 45 and 50 degrees, gap wedges between 50 and 54 degrees, sand wedges between 54 and 58 degrees, and lob wedges over 58 degrees.
The pitching wedge is the only wedge that comes standard with most sets of golf clubs. Players can hit the ball with it as far as 130 yards but by shortening their swing can pitch the ball accurately from much shorter yardage.
The gap wedge's advent filled the yardage "gap" between a pitching wedge and a sand wedge. The most skilled of players use these clubs when a sand wedge is too little club and a pitching wedge is too much.
The sand wedge can blast a ball out of a sand trap but can also loft the ball high and go as far as 100 yards when hit from a fairway or the rough.
A lob wedge makes it possible to get the ball up in the air and over hazards close to a hole. After clearing water, sand, or high rough, the ball will fall onto the green in a soft manner and stay on the putting surface.