This book covers comprehensively the Form 3 Computer studies syllabus. This book is structured with chapters that stand out relatively independently. The chapters are ordered according to the Kenya Institute of Curriculum Development (KICD) formerly Kenya Institute of Education (K.I.E.) syllabus. Great effort has been made to present a simplified and standard layout. Each chapter begins with a statement of the learning objectives. Additional material has been provided in the form of a glossary of computer terms. This is found at the end of the book.