There are a number of existing Wikipedia articles on bioinformatics and computational biology; the article on biostatistics is also helpful.

There is some disagreement on the proper uses of the following terms. The meanings intended by the author are summarized below:

Etymology: From the Ancient Greek βίος (bios), “‘life’”.
The science of the treatment of biological information, especially large quantities of biological information.
Biological System
A group of organs or organelles that work together to perform a certain task. (see [Wikipedia Biological System])
Biological Systems
A group of biological systems that work together producing an organism ie a living being, ie life
The sub-discipline of Bioinformatics concerned with probability and hypothesis validation on biological data. The term Biostatistics predates "Bioinformatics" considerably.
Computational Biology
Computationally-intensive methods to treat biological information. Generally this implies treatment of large amounts of data, but not always.
Control System
A device or set of devices to manage, command, direct or regulate the behavior of other devices or systems.
Control Systems of Biological Systems
A group of factors working to keep a group of organs balanced and still flexible enough to respond to hostile and variable environments
Functional Genomics
The study of functional information derived from entire proteomes; alternatively, high-throughput study of protein functions in general.
All the genes derived from one organism make up a single genome.
The study of information derived from entire genomes; alternatively, high throughput study of genes in general.
The science of information, the practice of information processing, and the engineering of information systems.
Any living system (such as animal, plant, fungus, or micro-organism). In at least some form, all organisms are capable of response to stimuli, reproduction, growth and development, and maintenance of homeostasis as a stable whole
All the proteins coded for by the sequences of a single genome, including their structures and functions, make a single proteome.
Structural Genomics
The study of structural information derived from entire proteomes; alternatively, high-throughput study of protein structures in general.