Accounts needs three things in place, all of which the setup wizard and Chapter 0 arrange: a chart of accounts (your company starts with the standard chart for its business profile), accounting periods covering the dates you post into, and — only if you trade in more than one currency — currencies and exchange rates (7.11).
Its neighbours are everyone. Sales, Procurement, Inventory, Manufacturing and the rest post their journals here automatically; the Finance cockpit and the dashboards (Chapter 2) read what is posted here; and the chart itself is maintained in System Setup (see 16.3) — this chapter is about using the books day to day, and 7.5 will point you to the chart's home at the moments you need it.