Not an Issue Updating plugins... persistant?

Hello,

I just recently started my own server, and I'm getting notices that some plugins have updates. I imagine this might be different from plugin to plugin, but generally, is it possible to update a plugin without wiping its configuration file?

Just as an example, I have the notifier plugin with a long list of messages I've configured. If I update that, will all of those messages need to be reinserted? Or can I just upload the new instance of the plugin and still have all of my previous settings still there?

Thanks!