From Bioinformatics.Org Wiki
Currently, a lot of bioinformatics work is concerned with the technology of databases (Thanks again to Ivanovi.) These databases include both "public" repositories of gene data like GenBank or the Protein DataBank (the PDB), and private databases, like those used by research groups involved in gene mapping projects or those held by biotech companies. Making such databases accessible via open standards is very important. Consumers of bioinformatics data use a range of computer platforms: from the more powerful and forbidding UNIX boxes favoured by the developers and curators to the far friendlier Macs often found populating the labs of computer-wary biologists.
Databases of existing sequencing data can be used to identify homologues of new molecules that have been amplified and sequenced in the lab. The property of sharing a common ancestor, homology, can be a very powerful indicator in bioinformatics (see below).