title: Can aggregate root reference another root?
body: <p>I'm a little bit confused. I just watched<br>
  Julie Lerman's Pluralsight video on DDD and here's the confusion I have:
  Having a simple online store example with:
  <strong>Purchase Orders</strong> with <strong>Items</strong> for <strong>Suppliers</strong>, what's the aggregate root here?</p>
  
  <p>Technically <strong>Purchase Order</strong>, right? It's for particular <strong>Supplier</strong> and has <strong>items</strong> on it. That makes sense.</p>
  
  <p>But.. is the Item an aggregate root as well? It has other "sub-objects" like "Brand", "Designer", "Color", "Type" etc... You might have a separate application in your SOA system to Edit and Manage items (without PO). So..in that case you will have to access a component of aggregate root - which is not allowed.</p>
  
  <p>Is the <strong>Item</strong> aggregate root in this example or not?</p>