What is external conflict in "content of the dead man's pocket", can u give me example, thanks

In Jack Finney's story "Contents of the Dead Man's
Pocket," there is certainly an external conflict between the protagonist, Tom Benecke,
and his surroundings, or "nature.  This type of conflict is called external because it
occurs between the character and an outside force; this particular kind of conflict is
commonly known as man versus nature.

In "Contents of the
Dead Man's Pocket," Tom struggles to make back into his apartment after finding himself
in a very dangerous and precarious position on the ledge outside his window.  When
attempting to retrieve an important work document, Tom steps onto the ledge outside his
window and follows the paper far enough to put himself in considerable
peril.