attachment vs affection

attachment and affection both are nouns.

Word	Noun	Adjective	Verb	Adverb
attachment	Yes	No	No	No
affection	Yes	No	No	No

As nouns, affection is a hypernym of attachment; that is, affection is a word with a broader meaning than attachment:

Other hypernyms of attachment include affectionateness, fondness, heart, philia, tenderness, warmheartedness, warmness.

attachment (noun)	affection (noun)
the act of fastening things together	a positive feeling of liking
the act of attaching or affixing something
faithful support for a cause or political party or religion
a supplementary part or accessory
a connection that fastens things together
a writ authorizing the seizure of property that may be needed for the payment of a judgment in a judicial proceeding
a feeling of affection for a person or an institution