Generic one is the use in English of the third person subject/object pronoun 'one', its genitive form "one's" and its reflexive pronoun form 'oneself' to refer to a generic individual. This is a common gender pronoun set, expressing personal agency and dual gender (covering both masculine and feminine).
This is considered formal in register, and mostly only used in formal writing. In speaking, most speakers prefer to use generic you.
'One's' is used with a genitive 's as a dependent possessive determiner, but not generally as an independent possessive determiner. As a dependent possessive determiner it uniquely uses an apostrophe, 'its' not doing so.
Present tense verbs in the indicative tense with 'one' as a subject must be inflected with the third person -s, e.g. "one has a duty" not e.g. *"one have a duty".
Its usage as a pronoun in English has been influenced by the similar, though unrelated French pronoun on.