A "Type Error" occurs in programming when an operation is performed on a data type that is not compatible with that operation. For example, trying to add a string, like "hello," to an integer, like 5, will result in a Type Error because these two types cannot be combined in that way. This error helps programmers identify issues in their code related to data types. Type Errors are common in languages like Python and JavaScript, where strict type checking can prevent unexpected behavior. To fix a Type Error, developers must ensure that the data types used in their operations are compatible, often by converting one type to another.