When started, it acts as the frontend to the functions offered by VirtualBox. The functionality is accessed with SOAPweb service requests.
The executable is a console program and runs until ctrl-c is pressed.
PS C:\Program Files\Oracle\VirtualBox> .\VBoxWebSrv.exe --help
Oracle VM VirtualBox web service Version 6.1.0
(C) 2007-2019 Oracle Corporation
All rights reserved.
Usage: vboxwebsrv [options]
Supported options (default values in brackets):
--help, -h: Print this help message and exit.
--host, -H: The host to bind to (localhost).
--port, -p: The port to bind to (18083).
--ssl, -s: Enable SSL/TLS encryption.
--keyfile, -K: Server key and certificate file, PEM format ("").
--passwordfile, -a: File name for password to server key ("").
--cacert, -c: CA certificate file, PEM format ("").
--capath, -C: CA certificate path ("").
--dhfile, -D: DH file name or DH key length in bits ("").
--randfile, -r: File containing seed for random number generator ("").
--timeout, -t: Session timeout in seconds; 0 = disable timeouts (300).
--check-interval, -i: Frequency of timeout checks in seconds (5).
--threads, -T: Maximum number of worker threads to run in parallel (100).
--keepalive, -k: Maximum number of requests before a socket will be closed (100).
--authentication, -A: Authentication method for the webservice ("").
--verbose, -v: Be verbose.
--pidfile, -P: Name of the PID file which is created when the daemon was started.
--logfile, -F: Name of file to write log to (no file).
--logrotate, -R: Number of log files (0 disables log rotation).
--logsize, -S: Maximum size of a log file to trigger rotation (bytes).
--loginterval, -I: Maximum time interval to trigger log rotation (seconds).