Bioinformatics has been recognised and studied as a separate discipline only in the last decade. Being a multidisciplinary subject it requires knowledge of several subjects, such as molecular biology, biochemistry, computer science and others. Students in a bioinformatics course are from different academic backgrounds; those who have studied biology (i.e., botany, zoology, biochemistry, microbiology, etc.), will require an introduction to mathematics and computer science, while those with a background in physics, chemistry and mathematics will need explanations of biological principles. This book provides a simple and concise explanation of the basic principles, tools and applications of bioinformatics. It explains subjects that are part of a conventional bioinformatics course, such as databases, database access and analyses tools principles of computer science that underlie the algorithms which are built into these tools. core algorithms of sequence analyses and phylogeny construction. Starting with a brief overview of biological terminology used frequently in bioinformatics, the contents are grouped into five sections: bioinformatics and algorithms databases and matrices alignment and comparison of sequences algorithms to analyse data applications of bioinformatics The book has been planned and structured as an undergraduate textbook for the one-semester foundation course in bioinformatics. In order to make the book more useful for a wider section of students and teachers, the book has been kept concise and relevant, at the same time covering all important aspects. Care has been taken to design the algorithms such that even beginners can understand them without difficulty.