energy function/loss function objective function cost function loss function likelihood function

https://en.wikipedia.org/wiki/Energy_functional
https://stackoverflow.com/questions/50342526/what-is-the-difference-between-energy-function-and-loss-function

objective function

cost function

loss function

https://en.wikipedia.org/wiki/Loss_function

likelihood function

In statistics, the likelihood function (often simply called likelihood) expresses how likely particular values of statistical parameters are for a given set of observations.