Summary: Automatic version check
The Launcher checks for new version of every startup by default, but can
disable thatr behavior with this option.
The version check means that the update server knows your IP address, how
often you start the Launcher, and what operating system your are running. No
personally identifying information is sent, but if you want to prevent the
Launcher from phoning home, you can do so.
Another reason to disable this option is if you want to say on an older version
on purpose, and don't want to be reminded to upgrade.