Apartments in group housing societies typically come with shared amenities such as security, parking and common areas, along with ongoing maintenance charges that fund their upkeep. They suit buyers who want managed living with less personal responsibility for upkeep.
Builder floors, on the other hand, usually mean fewer neighbours sharing a plot, more privacy, and often lower or no maintenance charges. They can also offer more flexibility in terms of layout, since each floor is typically a separate unit rather than part of a large tower.
Neither option is inherently better — the right choice depends on how much you value amenities and managed upkeep versus privacy and independence. Visiting both formats in the same locality before deciding often clarifies the decision more than research alone.