干细胞是一类尚未完全分化，具有自我更新和分化能力的细胞，主要包括胚胎干细胞和成体干细胞，具有强大的增殖能力和应用前景。文章系统阐述了干细胞的发现历程、主要生物学特性以及在临床治疗方面的研究进展。总而言之，干细胞作为再生医学的“种子”细胞，已经在临床应用上展现出了一定的潜力。随着技术的不断成熟以及评估和监管体系的完善，干细胞治疗有望成为一种更加安全和有效的治疗手段。

Stem cells, including embryonic stem cells and adult stem cells, are cells that retain differentiation potential and ability to self-renew. Here we describe the discovery and the main characters of stem cells. In a word, stem cells are the basic cell resource of regenerative medicine, and have shown great potential in clinical application. Following the development of the technology and evaluation system, stem cell therapy will be safer and more effective.