Customers

Not only that but orders and group pricing as well as the not-always-seen PayPal IPN.

So here's the access to both customers and orders with connections between the 2. Go to customers and you can access all the orders by the customer. Go to orders and you find the customer information.

Group Pricing is rarely used but can be handy if you want to give certain people a set discount.

If you are using PayPal IPN (not recommended actually), the list of orders will show up under here as well. That's because the IPN orders don't always make it back to the cart and you find yourself with only payments and no orders.