A4 is a standard paper size commonly used in many countries around the world. It measures 210 millimeters in width and 297 millimeters in height, which is approximately 8.27 inches by 11.69 inches. A4 paper is part of the ISO 216 standard, which defines various paper sizes based on the metric system. It is widely used for printing documents, letters, and reports. The A4 size is popular in offices, schools, and homes due to its versatility. It is suitable for both printing and writing, making it a preferred choice for everyday tasks. Many printers and copiers are designed to accommodate A4 paper, ensuring easy access for users.