The purpose of creating a White and Green Hiring Poster is to communicate a job opening to potential candidates using a visually appealing and informative design. The poster uses the colors white and green to represent the company's brand identity and features a clear job description, qualifications, and how to apply for the position. This poster aims to attract a diverse pool of candidates who may not have heard of the job opportunity through traditional channels and increase the chances of finding the best fit for the role.