Genes vs. Heredity

Genes or genetic mean something related to your DNA. Hereditary means something you inherit from your parents.
When kings die their child inherits the throne. That is hereditary, but it is not genetic, because there is no gene that makes a person royalty.
Not all genetic conditions are hereditary, such as if they are caused by a mutation they will not have been inherited.

Bottom Line, DNA is inherited, so genetic medical conditions are hereditary, but not all hereditary things are genetic.

Genetics vs. Genomics

Gene refers to a specific sequence of DNA on a single chromosome that encodes a particular product.

Genome encompasses the entire set of genetic information across all 23 chromosome pairs, including all genes, as well as gene-modifying sequences, and everything in-between.