The SVFileService provides support for an application to create or read separated value files.
Separated variable files are widely used to represent and exchange "flat" database information. Comma-separated values (CSV) and Tab-separated variables (TSV) are automatically supported or you can specify a value to be interpreted as the separator.
The SVFileService is not dependent on other services.
The POP3MailService overlaps the SVFileService to some extent. The READ command on the POP3MailService also allows processing of separator delimited files. Assuming the separated variable file you want to process is attached to an incoming email, the POP3MailService may be adequate for handling the processing of the file.
Similarly when SVFileService reads from or writes to a remote server an FTP connection is established to connect to the remote server. In this instance the SVFileService overlaps the FTPService to some extent.
When reading or writing from a remote file server, the SVFileService uses FTP to connect to the remote server.