Note cards are small pieces of paper, typically 3x5 inches or 4x6 inches, used for writing down information. They are often used by students and professionals to organize thoughts, study for exams, or prepare for presentations. Note cards can be easily shuffled and rearranged, making them a flexible tool for learning and brainstorming. These cards can be filled with various types of information, such as definitions, key concepts, or quotes. Many people use them in conjunction with flashcards for memorization or to create index cards for organizing research. Note cards are a simple yet effective way to enhance learning and retention.