Active components like transistors, BJTs, MOSFETs,  and integrated circuits (ICs) make it possible to control circuits. This video explains the must-have NPN and PNP BJTs. For MOSFETs there are a couple of N-Channels and P-Channels to consider. Basic ICs include some digital logic stuff from the 7400-family as well as the venerable 555-timer to have on-hand. We did not forget Op-Amps either. Spoiler: We do not recommend the ua741!

Whether you are just getting started in electronics or you have boxes of parts, it is good to know what are the most critical parts to have in your kit. James asked the element 14 community for what they considered to be essential passive components like resistors, capacitors, switches, wires, and even diodes. In this video, he consolidated their puts and explains what to think about when buying these parts for your kit.