Block format is a style of writing used primarily in business letters and documents. In this format, all text is aligned to the left margin, and paragraphs are not indented. Each paragraph is separated by a double line space, making the document easy to read and visually organized. This format is commonly used for formal communication, such as letters to clients or colleagues. It helps convey information clearly and professionally, ensuring that the reader can quickly identify key points without distractions from indentation or varied spacing.