CurrencyManager object

Binding is allowed on any IList. An IList is a list that allows certain operations, like adding an item, deleting an item, and getting the Nth item. What it doesn't have is knowledge of what item you're on (sometimes called Currency -- sorry, nothing to do with money). The form actually keeps track of what item you're on in each list using the BindingContext. If you have a TextBox with Text bound to your Customer's table's FirstName field, you could check _which_ FirstName you're looking at like this:
Console.WriteLine(BindingContext(customerTable).Position) 'if this prints 0, you're on the first
and you could change the current customer like this:
BindingContext(customerTable).Position = 5 'Move to the 6th customer (0-based)

BindingContext(customerTable) is a CurrencyManager.

You can also bind a property of a control to an object's property, like
TextBox2.DataBindings.Add("Text", Me, "Text")

BindingContext(Me) would keep track of the object you're bound to (in this case, it's just to see whether the property changes), and BindingContext(Me) would be a PropertyManager.