Here's a breakdown of their relationship:
* Physical Appearance: Katherine and Elena are almost identical, with only subtle differences in their features.
* Origins: Both are descended from the Petrova bloodline, which is known to produce doppelgängers.
* Significance: Katherine's resemblance to Elena is crucial to the plot, as it allows Katherine to impersonate Elena and gain access to the Salvatore brothers.
* Relationship: Their relationship is complex and filled with tension. While they are doppelgängers, they are also rivals. They both want the same things - love, power, and survival. However, their methods and motivations differ significantly.
Key aspects of their relationship:
* Katherine's manipulation: Katherine uses her resemblance to Elena to her advantage, manipulating others and causing chaos.
* Elena's confusion: Elena is constantly struggling with Katherine's presence and her own identity, especially as she becomes a vampire.
* Shared destiny: Their destinies are intertwined, as they are both targeted by various supernatural creatures and organizations.
While their relationship is mostly antagonistic, there are moments of understanding and empathy between them. They share a common origin and a connection to the supernatural world, which creates a unique bond despite their rivalry.