@angela There are a variety of factors that affect print quality with 3D printing. The quality of filament, filament diameter and type (PLA or ABS), how hot the internal temperature of the 3D printer gets in order to melt the plastic filament, the size of the 3D printing nozzle which lays the melted plastic and the speed at which the print takes place. Each of these elements influence the overall quality of the print and can affect how detailed of an object you are able to create.
At this time, there is no comparable quantifier, like DPI, that applies to 3D printing outcomes. Most professionals are interested in accuracy, stability, and surface texture as they measure what is called “total replication” or how closely a 3D printed object resembles the intended print.