Media planning involves determining how to use time and space to meet advertising objectives. Media buying is the process of identifying specific media outlets, negotiating costs, and handling payments. The central role of media research is to provide information on marketing, distribution, sales, competitors, media popularity and costs to inform media planning and buying. The goal of media planning is to expose the target audience to advertising messages at critical points using the optimal media mix, scheduling, and budget. Audience measurement tools like reach, frequency, gross impressions, and ratings are used to evaluate media selection and efficiency.