This lecture covers the introduction to NEMS, including examples and definitions. It discusses the fabrication techniques for NEMS, highlighting the challenges faced. The lecture also explores the reasons for using NEMS, focusing on size, mass, stiffness, and frequency. Additionally, it delves into the flexural and torsional aspects of NEMS, as well as the static and dynamic detection mechanisms. The challenges related to fabrication and measurement in NEMS are thoroughly explained, along with the importance of static and dynamic sensing. The lecture concludes with key takeaways and possible questions for further understanding.