The direction of a correlation is either positive or negative. In a negative correlation, the variables move in inverse, or opposite, directions. In other words, as one variable increases, the other variable decreases. For example, there is a negative correlation between self-esteem and depression. In other words, the higher your self-esteem, the lower your feelings of depression.
Excel Communications was founded in 1988 by Dallas entrepreneur Kenny Troutt as a long distance reseller in the US telecom sector at the birth of telecom deregulation.
Satoshi Nakamoto is the name used by the unknown person(s) who designed bitcoin and created its original reference implementation. As part of the implementation, they also devised the first blockchain database. In the process they were the first to solve the double spending problem for digital currency.