What are the 5 elements of ontology?

Could you please elaborate on the five key elements that constitute the foundational framework of ontology? Understanding the intricate nuances of these components is crucial for grasping the essence of this philosophical discipline. Are they perhaps the study of existence, properties, relations, categories, and instances? Or do they encompass alternative facets that shape our comprehension of being and the world around us? I'm eager to gain a deeper insight into how these elements intertwine to form the bedrock of ontology.