Wikipedia saysA model of computation is a formal description of a particular type of computational process. The description often takes the form  of an abstract machine that is meant to perform the task at  hand. What other forms can a model of computation take than an abstractmachine?What are the difference and relation between a model of computationand an abstract machine? I thought that they were the same, until I saw the the quote above.
A model of computation vs an abstract machine
terminology;computation models