The Enterprise Manager setup installs the set of features as defined by your license: for on-site deployments, these are usually Veeam Backup Enterprise Manager feature (which includes Enterprise Manager Web Site and Veeam Backup Enterprise Manager Server) and Veeam Backup Catalog, and for service providers - also Veeam Cloud Connect Portal.
If you are installing Veeam Backup Enterprise Manager on the Veeam Backup & Replication machine where Veeam Backup Catalog and/or Veeam Cloud Connect Portal is already installed, corresponding item(s) will be excluded from the list of components. For example, if you are installing Enterprise Manager to the machine where Veeam backup server runs, then Veeam Backup Catalog might be already installed there by Veeam backup server setup.
To learn about Veeam Cloud Connect Portal, refer to the product documentation at Veeam Help Center (https://www.veeam.com/documentation-guides-datasheets.html)
By default, these components will be installed to %ProgramFiles%\Veeam\Backup and Replication folder. Use the Browse button to specify the desired installation folder for installed components.