What is the difference between an error and a defect?

Error - is an incorrect action made by a person (programmer, tester, analyst, etc.) at the stage of design, coding, or testing. An error leads to the appearance of a defect in the software product.

Defect (Defect / Bug / Fault) - is the result of an error. It is a deviation of the actual behavior of the software from the expected, which is described in the requirements or design documentation. A defect can be detected at any stage of the software development lifecycle and potentially lead to a failure in the operation of the program.