Spray solvent?

Used for cleaning solder flux off boards after solder process. Often used in conjunction with flus cleaning brush or "Q-Tips".

Thermistors?

Some projects may use these. They are components that exhibit a resistance change with temperature. Now while all resistors show this property the thermistor will show much more change over a given range of temperature. One hopes the change is linear with temperature but this is often not the case. They can be used for sensing temperature or to help in building certain types of circuits where the resistance change affects the circuit in some beneficial way. One scheme could be to control speed of a fan based upon how hot of air the fan is moving.

DSub? connectors ;D shaped serial?

D Type connectors come in many sizes and pin counts. They are popular for projects because they are low cost, rugged design, easy to hand build cables and other characteristics. You will often see these referred to as "DB25" or "DB9".

Wall warts?

These are the small black power modules that attach to an AC wall plug and then produce a low voltage AC or DC power source. These may be a transformer implementation although in recent years there has been a strong trend toward the use of ligher weight switching types that direct rectify off the line.


Varistors?

Varistors are two terminal components that are designed to place into circuits that operate at voltages below the voltage rating of the varistor. If the voltage gets higher the component breaks down and conducts current in effect clamping the voltage in the circuit. One use of these is across AC line loads that may see narrow high voltage spikes that come from motors or relays. A properly selected and applied varistor could protect a piece of electronics equipment that is normally operating on 117VAC but could be damaged by 1500 spikes on the AC lines.

Michael Karas

NOTE: It is not necessary to have all those components and items that I listed to start any given project. But it would not be uncommon to have to buy at least some of the items based upon the nature of the project being undertaken.