An Automated Clearing House (ACH) is a network that facilitates electronic payments and money transfers between banks. It allows for the processing of large volumes of transactions, such as direct deposits, bill payments, and business-to-business payments, efficiently and securely. ACH transactions are typically processed in batches, which means they are collected and sent for processing at specific intervals. This system helps reduce the need for paper checks and manual processing, making financial transactions faster and more reliable for both individuals and businesses.