From Wikipedia:
Synthetic resins are materials with similar properties to natural resins—viscous liquids capable of hardening. They are typically manufactured by esterification or soaping of organic compounds.
Acrylic resins are a group of related thermoplastic or thermosetting plastic substances derived from acrylic acid, methacrylic acid or other related compounds.[1] Polymethyl acrylate is an acrylic resin used in an emulsed form for lacquer, textile finishes, adhesives and, mixed with clay, to gloss paper. Another acrylic resin is Polymethyl methacrylate which is used to make hard plastics with various light transmitting properties.(end quote)
So both are basically resin based but may be mixed with similar or other disimilar ingredients.