Definition - What does Standalone Server mean?
A standalone server is a server that runs alone and is not a part of a group. In fact, in the context of Microsoft Windows networks, a standalone server is one that does not belong to or is not governed by a Windows domain. This kind of server is not a domain member and functions more as a workgroup server, so its use makes more sense in local settings where complex security and authentication may not be required.
Techopedia explains Standalone Server
A standalone server provides local authentication and access control for any resources available from it, and it usually does not provide network logon services. This usually means that this kind of server uses a local user database and is available either in user mode or in share mode.
A standalone server does not require complex actions other than creating user accounts because it does not provide network logon services, which means that machines that log on to such a server do not need to perform a domain logon. The user or machine simply has to be associated with a known user to the server.
A scenario where a standalone server makes sense is for the distribution of files or documents in a local office setting. For example, an office wants to store design standards and reference documents that must not be altered but must be distributed, so a standalone server set to share mode and read-only mode is the best solution.