What is the difference between fixes and waypoints on an arrival plate?
As described in the answer to the previous question, all of the points on the chart are both waypoints and fixes. The difference between the printed icons is how they are identified from the air.

The waypoints marked by hexagons, some with darkened edges and some printed inside a square, note where the waypoint is on top of a VOR. This includes Razorback, Walnut Ridge, Gilmore, and Memphis. The icons with bolded sides are a VOR collocated with TACAN; inscribed inside a square notes a VOR collocated with a DME station.

Triangles are waypoints determined by a radial and distance from a VOR station. The star icons are determined by an RNAV (area navigation) system, which does not require the aircraft to fly a particular VOR radial to determine its course. Note that the procedure you provided is not available for RNAV-capable aircraft, likely because there is an RNAV arrival procedure that is preferred by ATC.



To fly the procedure, starting from the left, a pilot would identify the Razorback (RZC) point by their CDI showing that they had flown over the beacon itself. The next waypoint is MARBI; that is determined by flying along the 098 degree radial to a distance of 34 NM from RZC. Similarly, IGLOO can be identified by flying the 098 degree radial another 85 NM for a total distance of 119 NM. The distinct icons tell pilots how to identify the waypoints using their onboard equipment, but they otherwise have the same meaning.