How deep is the earth?

Could you please elaborate on the question, 'How deep is the earth?'" "I'm curious to know, what exactly do we mean by 'depth' when discussing the earth? Is it the distance from the surface to the core? Or perhaps the deepest point reached by human exploration? Also, are there any scientific measurements or estimations available for this? It seems like an intriguing concept to delve into, as the earth is a vast and mysterious place with layers of rock, soil, and possibly even undiscovered secrets lurking beneath its surface. Could you provide some insights on this topic?