This lecture covers the fundamentals of operational amplifiers (OPAMPs), including OPAMP voltage and current definitions, ideal transfer characteristics, and node-voltage analysis. It also delves into basic OPAMP circuits such as non-inverting, voltage follower, inverting amplifier, summing amplifier, and differential amplifier. The instructor explains the need for feedback paths in OPAMP circuits and discusses OPAMP non-idealities, simplified schematics, and the effect of finite gain-bandwidth product. The lecture concludes with examples of basic circuits combining OPAMPs with resistances and impedances.