MarvelClient is 100% transparent to the end-user – including the initial installation (when using the Mailbox Postopen Script option or corporate software deployment).
The whole management – and in many cases also the initial installation – is done from the Configuration database, your central control unit.

In general, MarvelClient is entirely invisible for end users, except for the following cases: 

• You choose for a Mailbased Install where the user needs to open the MarvelClient Install Mail
  (as opposed to using a Mailbox Postopen Script, where the user only needs to open his or her mailbox – also see Client Setup)
• You define Actions that access the server before the end-user has effectively logged into the Notes client
  (this would display a small password dialog during the client startup prior to the usual login dialog)
• You have created an Action that needs input from the end-user
• You display optional progress information during potentially lengthy Actions
• You have licensed MarvelClient Zip/Unzip or Attachment Blocking

See Also
MarvelClient: Good to know
System requirements
MarvelClient Components
How MarvelClient communicates with the server-side databases
The local MarvelClient file