We are currently updating our Oracle Databse and moving it to a different server. The name of the database will remain the same but the server name will be diferent. What would I have to do in order to reconnect the app (server) to the new database serve?

We are currently updating our Oracle Databse and moving it to a different server. The name of the database will remain the same but the server name will be diferent. What would I have to do in order to reconnect the app (server) to the new database serve?