Ok this may seem like kind of a newbie question, but here goes.

I'm using Amazon Web Services and created a Elastic Load Balancer for 2 instances that are identical EBS EC2 instances. We'll call these Server A and Server B. When a request for a file on the main load balancer, I'm assuming it balances the load between and pulls the file from either Server A or Server B. Now if I want to make a change to one of the site files on Server A. Do I then have to make the same change to Server B's file?