he'd / heed 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. 👇
he'd: NA
heed: (verb) pay close attention to; give heed to.
he'd: hh·IY·d
heed: hh·IY·d
(Examples are Wikipedia snippets under the CC ShareAlike 3.0 license. Definitions drawn from WordNet.)