Technical English, also known as simplified technical English, stands as a specialized controlled language crafted especially for industrial applications. Its primary objectives involve minimizing ambiguity, easing the process of translation, enhancing clarity, enabling smoother machine translation, and fostering improved comprehension. The core components of Technical English consist of two significant segments: the dictionary and the writing rules. This book attempts to understand the critical aspects that fall under the discipline of Technical English and how such aspects have practical applications. It is compiled in such a manner, that it will provide in-depth knowledge about the theory and practice of Technical English writing. This textbook will serve as a reference to a broad spectrum of readers.