Both POS Terminal (/admin/pos) and Checkout As (/admin/checkouts/new) load the exact same order-building screen — they're the same underlying screen running in two modes, and both require the Checkout As module to be turned on for your account (POS Terminal additionally requires the POS module). POS mode additionally: requires a cashier to select a POS Device and sign in with a numeric code on a keypad, requires a cash drawer to be opened before selling, adds a hamburger menu (Checkout, Customers, plus Transactions/Orders/Reports and, if you have Proposals, Proposals), and is meant to run continuously on a fixed terminal at a physical location. Checkout As is meant for staff placing a one-off order on behalf of a customer from a normal admin session — no device, drawer, code login, or hamburger menu. Orders placed through either one save as a normal checkout, so they appear in Customer Orders and Accounting.