Bioinformatics: The discipline of obtaining information about genomic or protein sequence data.
DNA: DNA (deoxyribonucleic acid) is the code that stores genetic information. It is a linear sequence (sometimes called string) of four bases (A,T,G,C). Humans have 23 chromosomes that contain our DNA. Put together, these chromosomes contain about 3.2 billion bases. For example, the DNA sequence below is the start of the human lamin B1 gene - AAAAGAAAAGGTTAGAAAGATGAGAGATGATAAAGGGT-CCATTT GAGGTTAGGTAA.
RNA:
RNA (ribonucleic acid) is similar to DNA in structure (there is a minor chemical difference) and is used to deliver the genetic code of DNA to the specialised parts of the cell (ribosomes) that synthesise proteins.
Genotype: The particular genetic encoding for an organism.
Phenotype: The expressed genotype of an organism. For example, you are the phenotype for your own particular genetic encoding and are the end result of your genetic code plus your environment (genotype + environment = phenotype).
Protein: Proteins are the macro-molecules that give all organisms their form, and are also responsible for many of the chemical processes in all organisms. Just a couple of examples are muscle contraction, vision, digestion of food and even intelligence and memory.