According to Texas Instruments, Op Amps are for Everyone. That is a tongue-in-cheek title for a popular and still relevant book on operational amplifiers, and while op amps are not for absolutely everyone, you do need to understand them if you are going to work with electronic circuits. They are popular and versatile components that have a high open loop gain, high input impedance and low output impedance. This section (work in progress) will have all the information, examples, and background that you need to know to begin to understand and use op amps in their many different configurations.
Background picture (LM741 Schematic): Omegatron via wikipedia.org
Background picture (Op Amp Circuits): Inductiveload via wikipedia.org