Bioinformatics involves the creation and development of advanced information and computational technologies for problems in molecular biology. It deals with methods for storing, retrieving and analyzing biological data such as nucleic acid (DNA/RNA) and protein sequences, structures, functions, pathways and interactions. In bioinformatics we aim at uncovering the wealth of biological information hidden in the mass of data to obtain a clear insight into the fundamental biology of organisms. This new knowledge has a profound effect on fields as varied as human health, agriculture, environment, energy and biotechnology. The subject matter of the book has been divided into 21 chapters in 3 sections. Section 1 deals with tools in bioinformatics in the form of biological, protein sequence, nucleic acid, metabolic pathway, biodiversity databases and sequence formats in biological databases. Section 2 studies methods in bioinformatics covering sequence analysis by computer programming, sequence alignment concepts and algorithms, multiple sequence alignment, similarity searches of biological databases, gene prediction, phylogenetic analysis, protein structure prediction and nucleic acid structure prediction. Section 3 focuses on organism specific bioinformatics covering genomic projects, bioinformatics of prokaryotes, fungal bioinformatics, plant genome databases and bioinformatics of animals. The book has been written in simple language and lucid style. The text has been supplemented with tables, figures and data boxes for easy comprehension by the readers. Abbreviations, Appendix and Index further enrich the book. The coverage and features make it an ideal textbook for students, teachers and researchers of bioinformatics.