In the book "Endless Forms Most Beautiful," by Sean Carroll the process by which genetic information is stored, copied, and decoded is related to the analogy of modern computer technology. DNA is comparable to the information stored on a computer's hard disk-drive; it is like a long term hard copy of genetic information. It is universal and is the basis of all kingdoms of life, from a tiny microscopic bacterium to a 6 ton elephant in Africa. DNA is the beginning of the central dogma. The central dogma is describing the process of protein production; from DNA to RNA to protein. To continue with our computer analogy, RNA is similar to the information stored in a cache because the lifetime of RNA is much shorter than that of DNA. RNA is simply used as a "messenger" to relay the genetic information for protein production, and the proteins are in essences the "programs" of the computer.
In complex organisms like humans, we have cells that perform different functions. For example we have red blood cells that carry oxygen, and these cells are different from our muscle cells. However, even though these cells have completely different structures and functions they are based upon an identical DNA sequence. How is this possible? Well, it is in the regulation of these genes and differential protein production that allows these cells to perform different roles in our bodies. The genetic information found in DNA is essentially "decoded" in two steps to produce different proteins. DNA is made up of two strands that consist of nucleotides with four distinct bases; complimentary base pair bonding is what holds the two strands together. Each "gene" occupies a certain region along the DNA strand. The gene is decoded in two steps, the first called transcription. During transcription a polymerase produces an RNA strand that is based on the DNA template. This RNA transcript is single stranded, based on the complimentary sequence of the DNA template and is termed "messenger RNA." In the second decoding step the messenger RNA (mRNA) is directly translated into an amino acid sequence that forms a protein. The amino acid sequence corresponds directly with the original DNA sequence, and that determines the specific folding, structure, and chemical properties of the protein which determines the protein's function. Although I am no computer expert, using Sean Carroll's metaphor, this decoding process can be related to the "decoding" of the information put into computer. The information or "code" is given to the computer, and the sequence of that code will be processed by multiple mechanisms in the computer and a "result" will be produced.