Which of the following statements is true about syntax errors?

Syntax errors are mistakes in the code that violate the rules of the programming language being used. When syntax errors exist, the code cannot be correctly compiled into an executable program. This is because the compiler cannot understand the instructions given due to incorrect formatting, missing punctuation, or other such inconsistencies. As a result, these errors must be fixed before the program can run at all.

The other statements are related to different types of errors or aspects of programming. For instance, execution errors occur during runtime when the code is syntactically correct but may lead to logical issues, while detection of syntax errors is generally straightforward as compilers typically provide error messages indicating where the code violates syntax rules. Finally, fixing a syntax error involves correcting the format or structure of the code rather than adjusting the program's logic.