What does this idiom mean?

[Vega]

Xkalibur seems to have hit the nail on the head, to use an idiom. This is called a forester's marking hammer.

I haven't found its meaning on the Free dictionary online and Google Dictionary. Could you make it clear or easier to understand?

Thank you in advance!

[Josef]

If you hit the nail on the head, you describe the exact nature of something such as a problem, a solution, or a situation.

For more information, including examples and quiz, please see hit the nail on the head in the EnglishClub.com Idioms Reference.

[Vega]

Thank you immensely!