The purpose of kerning, and most other typography is to make the printed or screen text more legible, that is, easier to read, and also more attractive.
ð ə WORD_BOUNDARY p ɜː p ə s WORD_BOUNDARY ʌ v WORD_BOUNDARY k ɜː n ɪ ŋ WORD_BOUNDARY æ n d WORD_BOUNDARY m oʊ s t WORD_BOUNDARY ʌ ð ə ɹ WORD_BOUNDARY t aɪ p ɑ ɡ ɹ ə f i WORD_BOUNDARY ɪ z WORD_BOUNDARY t ə WORD_BOUNDARY m eɪ k WORD_BOUNDARY ð ə WORD_BOUNDARY p ɹ ɪ n t ɪ d WORD_BOUNDARY ɔ ɹ WORD_BOUNDARY s k ɹ iː n WORD_BOUNDARY t ɛ k s t WORD_BOUNDARY m ɔ ɹ WORD_BOUNDARY l ɛ d̠ʒ ə b ə l WORD_BOUNDARY ð æ t WORD_BOUNDARY ɪ z WORD_BOUNDARY iː z i ə ɹ WORD_BOUNDARY t ə WORD_BOUNDARY ɹ iː d WORD_BOUNDARY æ n d WORD_BOUNDARY ɔ l s oʊ WORD_BOUNDARY m ɔ ɹ WORD_BOUNDARY ʌ t ɹ æ k t ɪ v WORD_BOUNDARY