What is a console war in video games?

Context: The video game console market started in 1972 with the release of the first home console, the Magnavox Odyssey. As more manufacturers entered the market and technology improved, the market began to coalesce around the concept of console generations, groupings of consoles with similar technical specifications that vied in the consumer marketplace. Since 1972, there have been nine such console generations, with two to three dominant manufacturers controlling the marketplace as an oligopoly.

As with most industries without a single dominant leader, console manufacturers have marketed their products in a manner to highlight them in a more favorable manner compared to their competitors', or to focus on features that their competitors may lack, often in aggressive manners. For example, console manufacturers in the 1980s and 1990s heavily relied on the word size of the central processor unit, emphasizing that games had better capabilities with 16-bit processors over 8-bit ones. This type of aggressive marketing led video game journalists to call the competitive marketing a "war" or "battle" as early as August 1988. As each new console generation emerged with new marketing approaches, journalists and consumers continued to use variations of the "war" language, including "system wars" and "console wars". By the early 2000s, the term "console war" was most commonly used to describe heated competition between console manufacturers within any generation.

Answer: 

In the video game industry, a console war describes the competition between two or more video game console manufacturers in trying to achieve better consumer sales through more advanced console technology, an improved selection of video games, and general marketing around their consoles. While console manufacturers are generally always trying to out-perform other manufacturers in sales, these console wars engage in more direct tactics to compare their offerings directly against their competitors or to disparage the competition in contrast to their own, and thus the marketing efforts have tended to escalate in back-and-forth pushes.