The difference between Addition and Affix

When used as nouns, addition means the act of adding anything, whereas affix means that which is affixed.

Affix is also verb with the meaning: to attach.

check bellow for the other definitions of Addition and Affix

Addition as a noun (uncountable):

The act of adding anything.

Examples:

"The addition of five more items to the agenda will make the meeting unbearably long."
Addition as a noun:

Anything that is added.
Addition as a noun (uncountable):

The arithmetic operation of adding.
Addition as a noun (music):

A dot at the right side of a note as an indication that its sound is to be lengthened one half.
Addition as a noun (chiefly, legal):

A title annexed to a person's name to identify him or her more precisely, as in "John Doe, Esq.", "Robert Dale, Mason", "Thomas Way, of New York".
Addition as a noun (heraldry):

Something added to a coat of arms, as a mark of honour; opposed to .

Affix as a noun:

That which is affixed; an appendage.
Affix as a noun (linguistic morphology):

A bound morpheme added to the word's stem's end.
Affix as a noun (linguistic morphology):

A bound morpheme added to a word's stem; the term comprises prefixes, suffixes, infixes, circumfixes, and suprafixes.
Affix as a noun (mathematics):

The complex number a+bi associated with the point in the Gauss plane with coordinates (a,b).
Affix as a noun (decorative art):

Any small feature, as a figure, a flower, or the like, added for ornament to a vessel or other utensil, to an architectural feature.

Affix as a verb (transitive):

To attach.

Examples:

"to affix a stigma to a person; to affix ridicule or blame to somebody"
Affix as a verb (transitive):

To subjoin, annex, or add at the close or end; to append to.

Examples:

"to affix a syllable to a word; to affix a seal to an instrument; to affix one's name to a writing"
Affix as a verb (transitive):

To fix or fasten figuratively; with on or upon.

Examples:

"eyes affixed upon the ground"

"rfquotek Edmund Spenser"