Punctuation errors occur when the correct symbols used in writing are missing, misplaced, or used incorrectly. These symbols, such as commas, periods, and question marks, help clarify meaning and structure in sentences. When punctuation is not used properly, it can lead to confusion or misinterpretation of the text. Common types of punctuation errors include run-on sentences, where two independent clauses are joined without proper punctuation, and comma splices, where two sentences are incorrectly connected with just a comma. Understanding and correcting these errors is essential for clear and effective communication in writing.