An update source is a resource containing updates for Kaspersky Web Traffic Security databases.
The main update source is Kaspersky Lab update servers. These are special Internet sites that contain updates for databases and application modules for all Kaspersky Lab applications. If you connect to the Internet via a proxy server, you need to configure the proxy server connection settings.
To reduce the amount of Internet traffic, you can configure updates of Kaspersky Web Traffic Security databases from a custom update source. User-defined HTTP- or FTP servers or local folders on your computer can serve as custom update sources.