What is the difference between a possessive adjective and a possessive pronoun?

Possessive adjectives are very similar to possessive pronouns, but there are differences between them: 

• Possessive adjectives (“my,” “your,” “his,” “her,” “its,” “our,” “their,” and “whose”) precede the noun that they modify (e.g., “my ticket,” “their sister”).   
• Possessive pronouns (“mine,” “yours,” “his,” “hers,” “ours,” “theirs,” and “whose”) replace a noun and stand on their own (e.g., “That’s mine!” “Which one is his?”).