como mencionei no comentário:
como menção do link da Wikipedia: Nos sistemas operacionais Windows NT, um serviço do Windows é um programa de computador que opera em segundo plano. [1] É semelhante em conceito a um daemon do Unix.
Um daemon é um tipo de programa em sistemas operacionais Unix-like que é executado discretamente em segundo plano, em vez de sob o controle direto de um usuário, esperando para ser ativado pela ocorrência de um evento ou condição específica.
Nos sistemas operacionais Microsoft Windows, os programas chamados serviços executam as funções dos daemons, embora o termo daemon agora esteja às vezes sendo usado com relação a esses sistemas também.
fonte: link
UPDATE (Mais detalhes e comparação real):
- UNIX: A daemon is a process that detaches itself from the terminal and runs disconnected in the background, waiting for requests and responding to them.
- Windows: A service is a special type of application that is available on Windows and runs in the background with special privileges.
- In UNIX, a daemon is a process that the system starts to provide a service to other applications. Typically, the daemon does not interact with users. UNIX daemons are started at boot time from init or rc scripts. To modify such a script, it needs to be opened in a text editor and the values of the variables in the script need to be physically changed. On UNIX, a daemon runs with an appropriate user name for the service that it provides or as a root user.
- A Windows service is the equivalent of a UNIX daemon. It is a process that provides one or more facilities to client processes. Typically, a service is a long-running, Windows-based application that does not interact with users and, consequently, does not include a UI. Services may start when the system restarts and then continue running across logon sessions. Windows has a registry that stores the values of the variables used in the services. Control Panel provides a UI that allows users to set the variables with the valid values in the registry. The security context of that user determines the capabilities of the service. Most services run as either Local Service or Network Service. The latter is required if the service needs to access network resources and must run as a domain user with enough privileges to perform the required tasks.