What errors are detected by compilers?

Compilers typically detect three main types of errors: syntax errors, which occur when the code violates the grammatical rules of the programming language; semantic errors, which arise when the code is syntactically correct but has logical issues (like type mismatches or undefined variables); and linkage errors, which happen when the compiler cannot resolve references to variables or functions due to missing definitions or incorrect scope. These errors help ensure that the code adheres to the language's rules and can be executed correctly.