Bioinformatics is the field of science in which biology, computer science, and information technology merge to form a single discipline. According to genome.gov, "Bioinformatics is the branch of biology that is concerned with the acquisition, storage, and analysis of the information found in nucleic acid and protein sequence data. Computers and bioinformatics software are the tools of the trade."
Advances in DNA sequencing have created a vast amount of data to analyze, and bioinformatics offers a means of combining all of this information to form a comprehensive picture of normal cellular activities so that researchers may study how these activities are altered in different disease states. The ultimate goal of the field is to enable the discovery of new biological insights as well as to create a global perspective from which unifying principles in biology can be discerned.
Bioinformatics is a young and dynamic science. New bioinformatic software is being developed while existing software is continually updated.
The following are useful sites for a good introduction to and overview of the subject:
This section of the National Human Genome Research Institute (genome.gov) website demonstrates finding genes, finding functions and examining variation through the use of bioinformatics.
Introduction to Bioinformatics
A 2010 slide presentation to a Bioscience class by the Chair of the Department of Computer Science & Engineering at Lehigh University.