I have published my webapplication in a new website on my local IIS for testing, I now have created a newer version and I need to publish it without deleting the older version.
Can I publish it as a new application on the same website ? Will this cause any conflicts or errors with the existing version being in the same application pool ? Or should I publish it as a new website ?
If you are overwriting a previously published app/website you should remove all contents of the previous version to ensure that it is a clean install. If you overwrite, you run the risk of potential files and folders lurking if they have been removed in your current version.
You can always of course publish to a new site. This causes no harm for a dev application.