This lecture covers the fundamentals and applications of High-Resolution Transmission Electron Microscopy (HRTEM), including topics such as image formation, contrast transfer function, weak phase object approximation, and the role of optical systems in creating high-resolution images. The instructor discusses the importance of spherical aberration correction, the impact of defocus on image quality, and the challenges in interpreting HRTEM images. Examples of HRTEM imaging techniques, such as phase reconstruction and crystal structure analysis, are also presented.