Arbitrary-Precision Arithmetic is a method used in computing to perform calculations with numbers that have a very large number of digits. Unlike standard data types, which have fixed limits on size, arbitrary-precision allows for calculations on numbers that can grow as needed, making it useful for applications requiring high accuracy, such as in cryptography or scientific computing. This technique is implemented using specialized libraries or software that manage the storage and arithmetic of these large numbers. By breaking down operations into smaller, manageable parts, arbitrary-precision arithmetic ensures that even the smallest fractions or the largest integers can be handled accurately, regardless of their size.