E-waste, simply put, is short for electronic waste. The U.S. EPA synonymies e-waste with "e-scrap" and "end-of-life electronics" as well. Typical examples of e-waste include computers, electrical equipment, phones, and headphones.
But why the separate title? Why can't e-waste just be labeled as regular waste? Well, because most electronics have two unique attributions: being very bad for the environment, and being incredibly hard to recycle. This is exactly what the Oxford Dictionary details about e-waste, including in the definition, "typically containing environmentally hazardous substances and requiring special treatment for safe disposal or recycling."
These attributions are the cause for a very important questions: what does e-waste actually do to the environment? As described by the U.S. Public Interest Research Group, about 6.9 million tons of e-waste is generated in just the U.S., and if not recycled properly, will lead to hazardous materials such as battery acid, lead, and mercury leaching into local soil and groundwater.
Unfortunately, talking about how electronics are recycled is heavily complicated and heavily boring. However, I can surely talk about how little e-waste is actually recycled. According to the WHO (not the band), less than a quarter of e-waste was properly documented and recycled globally. A QUARTER... GLOBALLY. It doesn't necessarily matter how e-waste is recycled if it ain't being recycled in the first place.
Now that the problem is properly in context, it's time to consider one of the biggest contributors to e-waste, one that will shape future research and put a spotlight on big tech companies. That contributor is a little concept called planned obsolescence.
Planned obsolescence, as described by Wendy Hamblet in the Salem Press Encyclopedia of Science, is designing and building a product in a way that ensures the owner seeks to replace it after a certain amount of time. This concept applies to all products, but lately the term is most associated with electronic devices.
Given the definition has an implicit incentive structure to make a product last for less time in order to sell more products, it's no shock that this concept can be seen in most big technology companies who sell highly valuable (expensive) devices. The biggest offenders are companies that make a new product every single year (cars, phones, computers), subsequently arbitrarily removing support for an older product (just look at Apple for an example).
As stated previously, planned obsolescence will be a major focal point when analyzing tech companies, comparing what they say about being environmentally friendly, versus what they actually do with their products and advertising.