Which allele is dominant and which one is recessive? And on what basis is it decided? And what exactly is allele, dominant and recessive in simple language.

Which allele is dominant and which one is recessive? And on what basis

1.	Which allele is dominant and which one is recessive? And on what basis is it decided? And what exactly is allele, dominant and recessive in simple language.
Answer» Which allele is dominant and which one is recessive? And on what basis is it decided? And what exactly is allele, dominant and recessive in simple language.