Do I need a diffuser?

I've NEVER used a diffuser before (or to be honest, even heard of it). I had my hair relaxed since I was very little and just let the salon handle all the upkeep. I'm looking for ways to dry my hair faster....i have an old conair blow dryer but no diffuser.

My question is, is it damaging to use just the hair dryer? I've already used it a few times this week but now I've gotten paranoid. When I looked up diffusers to try to find an answer I saw alot of references to helping hair clump, be curlier, tossed around less....but no info on damaging compared to regular dryer. This is just blowing the air about six inches from my hair to dry it faster.....I'm not really that concerned about "keeping" my clumps, etc., at the moment so that's not priority. I just want dry hair WITHOUT will blow drying my hair (no tension or styling) cause any harm without a diffuser??

4a?? Maybe 3c...some 4b??? No clue

tiny s-waves, coils, and spirals

- Cleanser: CJ Daily Fix or KC Come Clean
- Co-wash: Suave Naturals or V05
- RO: GVP Conditioning Balm or Tresemme Naturals
-Stylers: Garnier Pure Clean Gel, CJ Aloe Fix, KCCC

"I remember your childhood hair....flowin' wild at the county fair" - kelley stoltz

"and all the hours that you've been sitting at your vanity....may they carry you far from your misery" - conor oberst