Rezi AI resume editor is an AI-based resume builder that helps to create and improve resumes. It offers features such as writing and editing resume content, generating summaries and cover letters, keyword targeting, and real-time content analysis. Users can access Rezi AI writer by creating a free Rezi account and subscribing to Rezi Pro or purchasing AI credits. The tool employs GPT-3 technology and offers sample resumes, cover letters, and resignation letters as examples. Pricing information is available for the different features and AI credit usage.