Why won’t certain coilovers fit my car?

I have a 1996 Toyota Camry and it’s my first car i’m working on and modifying so i’m lacking quite a bit of knowledge about this. I saw good reviews for the ‘Tein Street Basis Z Coilover Kit’ and figured it was a reliable cheaper option to get to begin learning how to work on my car, but FitmentIndustries is saying it won’t fit on my car, why is that?