With WooCommerce Payments, after a customer makes a purchase through your store, the funds from that transaction are placed into a pending balance on your account.
Normally, the funds in your account are subject to a standard pending period, after which they are made available for the next upcoming deposit. You can change the deposit schedule if you wish, between daily, weekly, and monthly. Scheduled deposits such as these can take a day or more to arrive in your bank account. There are no extra fees for these regular deposits.
With Instant Deposits, you can request some or all of your available balance to be deposited immediately, up to a daily maximum. These deposits can only be made to debit cards, and are subject to an additional fee, but the funds will arrive within minutes. Please see the linked documentation on Instant Deposits for more information.