伟大 means 'great' in the sense of being admirable, inspiring, or historically significant — used for people, achievements, or ideas. Unlike 巨大 (jù dà, huge in size) or 重要 (zhòng yào, important in a practical sense), 伟大 carries emotional weight and praise. It's more abstract and noble than 宏大 (hóng dà, grand in scale) or 盛大 (shèng dà, grand in ceremony).