Genes are smaller pieces of chromosomes, which are contained in the nucleus of a cell. Genes hold the secret to deciding all your physical and chemical traits within your body, they literally are the blueprint for the construction of your body. They instruct things such as your eye color, your body type, your hair color, skin color, your body type, blood type, you get the idea. Gene may be homolgous, meaning they are coding for the same trait, or may be heterozygous, meaning one is coding for the dominant form of the trait, while the other one is coding for the recessive, or hidden form of the trait. Current technology is trying to get to the point of being able to manipulate the genetic code within organisms to dictate specific traits in that organism. This is called genetic engineering.
Gene are the functional unit of DNA. That is they are they segment of of DNA that code for a particular proteins.
They are inheritable characters. Genes hold the information to build and maintain an organism's cells and pass genetic traits to offspring, although some organelles (e.g. mitochondria) are self-replicating and are not coded for by the organism's DNA.