Question
There are five technology-related concepts called "Redshift" or "red shift." What is the difference between them?
Answer
We hope to provide a thorough disambiguation of the term "Redshift" or "red shift."
In physics we know that visible light has a wavelength. Depending on the color we see, the wavelength can be longer or shorter than others. The longest wavelength is red (according to this page https://socratic.org/questions/what-color-of-light-has-the-longest-wavelength). When objects in space move closer to a telescope, their wavelengths shorten and the light appears to be more blue (according to this posting https://www.space.com/25732-redshift-blueshift.html that worked). When objects move farther away, they appear to be more red as the movement affects one cycle of a wave. That is the trajectory increases the length of one wavelength so the visible color is more red (Space.com).
There is an economics of technology concept called "red shift theory" that was coined by Greg Papadopoulos (Informationweek.com). This theory states that companies that use vastly more servers and I.T. infrastructure than normal companies will grow more rapidly than normal companies (Informationweek.com). It is interesting to note that before 2008, he in effect predicted that Hadoop would satisfy the heavy demands of businesses. He thought that large numbers of commodity (or low cost) servers could overcome the limitations of Moore's Law (Informationweek.com). (In some articles there is no space between the words "red" and "shift" when referring to Papadopoulos's theory. In some articles words are in uppercase.) To learn more about this term, see this link (Zdnet.com).
Amazon Redshift is a data warehouse PaaS offering for AWS. It is based on PostgreSQL and the company ParAccel's technology (Wikipedia.com). The color "red" can refer to Oracle's red logo; Oracle is nicknamed "Big Red" and this is the source of the term Redshift (according to a Quora answer).
Redshift is also a collection of astronomy software applications that can be used in planetariums or used to control telescopes. To learn more see this external link or Wikipedia.
There is a Linux application called Redshift. It is designed for the GUI desktop of Linux. Redshift changes the color display throughout the day based on your geographic location and the season. It makes it easy on the user's eyes and helps prevent insomnia. To learn more about it, see this website, the main GitHub site for the project or Wikipedia.