This document summarizes the key differences between HR certifications, what is required to get certified, how to study for the exam, and maintaining certification. It discusses that the PHR certification focuses on tactical HR skills, the SPHR emphasizes strategic skills, and the GPHR addresses international HR practices. Candidates must meet education and experience requirements and pass the exam. Studying options include free and paid resources that provide the body of knowledge covered on the exam. Recertification requires ongoing professional development activities every three years like continuing education, projects, research, or membership. Certification demonstrates assurance of learning and is important for the HR profession.