The book is written for an undergraduate course on Hardware Description Languages. It provides comprehensive coverage of the VHDL (VHSIC-HDL, Very High Speed Integrated Circuit Hardware Description Language). It also introduces Verilog HDL. The book uses plain and lucid language to explain each topic. A large number of programming examples is the feature of this book.The book explains the structure of VHDL module, operators, data objects, and data types used in VHDL. It describes various modeling styles - Behavioral Modeling, Data Flow Modeling, Structural Modeling, Switch-Level Modeling, and Mixed-Type Descriptions, with important concepts involved in them. It also introduces the structure of the Verilog HDL module, operators, data types, and compares VHDL and Verilog HDL.