So I never paid attention to the high porosity low porosity thing. Just didn't give it much thought because I didn't understand how that impacted the performance of my hair. And honestly, I still don't really know what it means lol.
But I put a few clean strands of hair in a cup of water about 10 minutes ago, and it's just a floatin.
Research ensues.........
Porosity is important because it can determine what type of products and care your hair will likely need.
High Porosity: Your cuticles are raised, you absorb moisture really well, but have trouble retaining it. You'll likely need regular protein treatments (to fill gaps in cuticle), heavier products, and to seal your hair after moisturizing. You probably won't need heat to get products to absorb. Hydral fatigue (hair taking in too much water too quickly, causing swelling) could be an issue, so prepooing may be a good idea.
Low Porosity: Your cuticles are tightly closed. Moisture is hard to absorb, but easier to retain. Protein should be used infrequently, light products will absorb easier than heavy ones, heat will work best for absorption, product buildup is a problem which will require regular cleansing.
Normal porosity: well, its in between. Moisture is accepted better than low porosity, but retained better than high porosity (but not as well as low).
I hope this helps.