In this lesson, the focus is on the careful installation of a CPU (Central Processing Unit), which is an electrostatic sensitive device. It’s crucial to use anti-static equipment, such as wristbands, to prevent damage during installation. The instructor explains the importance of handling pins delicately and ensuring the CPU is correctly aligned with the motherboard’s socket, using arrows for guidance. Additionally, thermal paste should be applied correctly to avoid overheating, and once the CPU is installed, the heatsink and power connections must be set up properly to ensure the computer functions effectively.