Here's the context for this question: for example, if I were a Wizard that learned Healing Word from Magic Initiate feat, does that spell count as a Wizard Spell that goes off of Wisdom or something or is it per say a Cleric or Druid spell?

Here's another proposition, if I were cast Firebolt as a Cleric and I got Firebolt from like the Strixhaven initiate feat and chose Wisdom for my spell casting modifier, is it a Cleric spell for me and would I get the extra damage from the lvl 8 feature some Clerics get called Potent Spellcasting?

Or by the end of the day, is a spell such as Fire Bolt just considered to be a Artificer, Sorcerer, and Wizard spell regardless where they came from with the ONE exception I can definitively find being through the Bard's class feature of Magical Secrets where it deliberately states that it becomes a Bard spell for you?