The document provides definitions and explanations of different types of language tests: - Achievement tests measure how well students learned material from a class. - Diagnostic tests identify students' language problems or strengths. - Objective tests have single correct answers while subjective tests use examiner judgment. - Placement tests determine students' levels to find the best class. - Proficiency tests measure language ability without focusing on class content. - Progress tests assess learning at intervals, like weekly, during a course.