What is a genotype?

What are the traits a genotype is responsible for and how they manifest?

Genotypes and Phenotypes are basic terms of genetics.
Understanding Phenotypes will help you understand Genotypes better.
Phenotypes are visible manifestations of traits (skin color, height, hair color).
Genotype is the genetic constitution of a phenotype.
Example:
There are two genes, one is dominant and the other one is recessive.
The dominant gene (let’s name it S) is responsible for brown hair, while the recessive gene (s) is responsible for blonde hair.
The combination SS will result in brown hair. So will Ss. Only ss will result in blonde hair.
Hope this explains it well.