Annotating text involves writing notes in the margins or text to engage actively with content. It helps reduce and organize information, identify key concepts, and monitor learning. Annotations should restate main ideas, ask questions, make comparisons, and challenge ideas. Highlighting alone is insufficient - written notes in the annotator's own words are needed. The four main types of annotations are restatement, questioning, compare/contrast, and challenging ideas. Annotations can clarify confusing terms, connect to personal experiences, and note inconsistencies.