Short answers, pulled from the story.
Werner Heisenberg coined the phrase Copenhagen interpretation around 1955 while criticizing alternative interpretations developed by David Bohm. He delivered lectures titled The Copenhagen Interpretation of Quantum Theory and Criticisms and Counterproposals to the Copenhagen Interpretation in 1955.
The city of Copenhagen refers to where Bohr and Heisenberg worked during the mid-1920s. Physicists worked with approximations until the mid-1920s when the revision reached coherent status after decades of heuristic corrections.
Formulated by Max Born in 1926, the Born rule gives the probability density of finding a particle at a given point when measured. This probability is proportional to the square of the magnitude of the particle's wave function at that point.
Einstein maintained that quantum theory could not be complete despite giving correct predictions and famously said he was convinced God does not throw dice regarding randomness in nature. His most famous product was the Einstein-Podolsky-Rosen thought experiment published on the 2nd of May 1935 which pointed out flaws in their reasoning.
In Copenhagen-type views, there is a 50% chance the cat will be dead and 50% chance it will be alive before the box is opened to check on it. The description of the cat during the course of the experiment becomes a blur of living and dead cat states until observed.