This book discusses information theory as a means of extracting data from large amounts of biological sequences. Utilizing the Shannon theory, the book explains using the information theory principles to interpret sequences and extract vital information. It provides a detailed overview of the practical applications in bioinformatics and includes coverage of diversity in nucleotide and amino acid sequences, sing-nucleotide polymorphism (SNP) and indel sites, binding sites in promoter regions, splicing sites, and more.