As an interaction designer working with electronics, your goal is usally on creating and evaluating the user-experience of a product, not on spending long nights in the electronics lab.
This is where integrated circuits (ICs) enter the game. An integrated circuit essentially contains a variety of different low-level components, all wired up and combined into a small package with clearly defined inputs and outputs. This hides much of the low-level complexity found and allows you simplify your electronic design. Integrated circuits are available for many different purposes (e.g. sensors, motor-drivers, multiplexers, etc.) and come in different sizes and shapes (“packages” or “footprints”).
The more recent ICs are often made for use in mobile devices and therefore often too small to be soldered by hand. This is where a variety of manufacturers (such as Sparkfun, Adafruit, Seedstudio and others) offers them conveniently mounted on hand solderable breakout boards, often even in combination with code libraries specifically written for each IC. The libraries and the circuit designs are often released as open-source and can be modified by the community.
If you have ever wondered what exactly is inside of such tiny, seemingly magic, blackboxes and how they are made, here is the answer: