noun
General word for visible evidence left behind: footprints, stains, marks, or any sign that something was there.
雪の上に動物の足跡が残っていた。
Animal tracks were left in the snow.
犯人は何の跡も残さずに逃げた。
The culprit fled without leaving any trace.
noun
Refers to the location where something once existed, especially historical ruins or the former site of a building.
ここはかつて城があった跡です。
This is the site where a castle once stood.
遺跡の発掘調査が行われている。
Excavation work is being carried out at the ruins.
noun
Only when written 痕
Specifically a physical scar or lingering mark on the body or an object; often written 痕.
手術の痕がまだ少し残っている。
The scar from the surgery still remains a little.
The historical derivation is uncertain; the kanji 跡 is conventionally associated with footprints, traces, and remains.