Alleles: These are the various forms of the same gene. Like having multiple versions of a recipe - one for vegan chocolate cake, another for gluten-free chocolate cake, etc.
Genotype:This is the genetic makeup or set of genes in our DNA which is responsible for a particular trait. It's like having all the ingredients listed in your recipe.
Phenotype:This is the physical expression, or characteristics, of that trait. The phenotype would be the actual baked cake you can see and taste.