What is the Certified Pool/Spa OperatorÂ® Certification Program? A CPOÂ® Certification provides individuals with the basic knowledge, techniques, and skills of pool and spa operations. This training has helped protect millions of swimmers by reducing hazards at aquatic facilities.
A year is the orbital period of the Earth moving in its orbit around the Sun. Due to the Earth's axial tilt, the course of a year sees the passing of the seasons, marked by changes in weather, the hours of daylight, and, consequently, vegetation and soil fertility.
A centennial refers to the 100th year, so it itself is only one year. If it was 100 years since the birth of someone or some historical event, this year would be regarded as the centennial year. A century refers to a complete set of 100 years. 2 people found this useful.