Ndimofor, Aretas N.: - Aretas Ndimofor is an educator and a social entrepreneur from the North West Region of Cameroon. He holds a BSc in Geology, Mining and Environmental Science from the University of Bamenda and a Teaching Diploma in Geology (Dipes I) from the Ecole Normale Supérieure (Annex), Bambili. He is also a Microsoft Office Specialist Master (MOSM) in Office 2013 and 2016, a Microsoft Innovative Educator (MIE), a Google Certified Digital Marketer and Graduate from the School of Entrepreneurship and Economic Development Studies (SEEDS) of African Dreams (CEMMED). He has been teaching geology in secondary and high Schools since September 2009 and was the head of the Geology Department of Government High School Njinikom, Cameroon from 2013 to 2016. This textbook is inspired by his expertise in the area and his experiences teaching geology in schools in Cameroon. He is founder of TC Techies (Twenty-first Century Techies), an initiative focused on the promotion of Digital Literacy and certification for youths, and CERTINED (Certified Innovative Educators), which trains educators on e-learning design. He enjoys reading personal development books, listening to music and motivational tapes, dancing, creating e-learning tutorials, video and sound editing, networking and helping others in the area of personal development.