The difference between Dude and Fop

When used as nouns, dude means a man, generally a younger man, whereas fop means a vain man.

Dude is also verb with the meaning: to address someone as dude.

check bellow for the other definitions of Dude and Fop

Dude as a noun (chiefly, US, colloquial):

A man, generally a younger man.

Examples:

"So we were at the mall and these two dudes just walk up to us and say "hi"."
Dude as a noun (colloquial, used in the vocative):

Examples:

"'Dude, I'd be careful around the principal; he's having a bad day."

"Watch it, dude; you almost knocked me over."
Dude as a noun:

An inexperienced cowboy.
Dude as a noun (slang):

A tourist.
Dude as a noun (archaic):

A man who is very concerned about his dress and appearance; a dandy, a fop.

Dude as a verb:

To address someone as dude.
Dude as a verb:

To take a vacation in a dude ranch.
Dude as a verb (US):

Usually followed by : to dress up, to wear smart or special clothes.