Checking the order

Hello,

I’m working through this course and I’m on the checking the order topic.

Rather than pushing forward, there is something I can’t grasp.

I am having difficulty understanding

When the function finds an index that is greater than or equal to minIndex, it will return that index plus 1.

What is this function comparing in this section? What needs to be greater than or equal?

How can a letter be greater than?

Thanks in advance!