Midjourney is a generative AI image tool that creates images from text prompts. You write a description ("A cyberpunk city at night, neon signs, raining, cinematic lighting"), Midjourney generates 4 variations, you pick the best and refine (request variations, upscale, edit). The tool produces high-quality, artistic images that typically require a professional illustrator 5-20 hours to create manually. The workflow: craft prompt → submit in Discord → view 4 variations → pick one → upscale or refine → export. Entire process 5-10 minutes per image.