Short answers, pulled from the story.
Parinirvana marks the end of all karmic cycles for a being who has already achieved nirvana during their lifetime. This state involves the dissolution of the skandhas and stops the process of rebirth completely.
Early Pali texts like the Mahaparinibbana Sutta describe the Buddha's death at Kusinagara as a biographical event. Scholar Andre Bareau notes that the oldest core components focus solely on this location and subsequent funerary rites.
The Mahayana Mahaparinirvana Sutra dates to the second century CE or later according to scholars like Masahiro Shimoda. This text uses the Buddha's illness and Cunda's meal offering merely as a springboard for expressing standard Mahayana ideals.
Scholar L A Waddell suggested the site of Gautama Buddha's death might lie north of Bettiah near Rampurva in Bihar. He believed Kusinagara could be found along the line of Ashoka pillars leading from Patna despite no definitive physical evidence confirming the exact spot today.
Gandhara art from the second to third centuries shows the reclining Buddha figure surrounded by disciples. Reclining statues became the standard visual representation for this specific moment in Buddhist history across East Asian cultures.