Cognitive biases describe flawed thought processes, whereas logical fallacies describe errors in argumentation.
A cognitive bias describes a common error in judgment. Examples of cognitive biases include confirmation bias (i.e., the tendency to seek out information that confirms one’s beliefs) and the halo effect (i.e., the tendency to assume that someone who exhibits one positive attribute, such as beauty, also has another positive attribute, such as honesty).
A logical fallacy is a type of flawed argument. Many logical fallacies either result from or intentionally appeal to cognitive biases.