How is 'Jared' greater than 'Brittany'?

Question

I'm looking in my book, and it doesn't explain it. Its telling me what a binary search tree is and it decided to use strings.

         Jared
        /     \
 Brittany      Megan
 /      \        /   \
Brett  Doug     Jim  Whitney

So supposedly, a node is greater than its left subtree and lesser than its right subtree. How is Jared greater than Brittany?