Roughly, the definition of 'genotype' is a description of genetic characteristics or makeup. Phenotype can be described as the resulting physical characteristics subsequent to genotype. This means that differences in genetic makeup could greatly influence how something, such as an embryo, develops.
Comment: I use a memory aid for this ind of thing, as I easily get them mixed up. Simply use the two letters of each word. Genotype --> genetic, and phenotype--> physical. Hope I answered your question.