son / sun are similar-sounding terms with different meanings (referred to as homophones). To better understand the differences, see below for definitions, pronunciation guides, and example sentences using each term. 👇
son: (noun) a male human offspring. (noun) the divine word of God; the second person in the Trinity (incarnate in Jesus).
sun: (noun) the star that is the source of light and heat for the planets in the solar system. (noun) a person considered as a source of warmth or energy or glory etc. (noun) any star around which a planetary system revolves. (verb) expose one's body to the sun. (verb) expose to the rays of the sun or affect by exposure to the sun.
son: s·AH·n
sun: s·AH·n
(Examples are Wikipedia snippets under the CC ShareAlike 3.0 license. Definitions drawn from WordNet.)