Welcome to the installer! Here you will find a nice big friendly logo for your Linux distribution. Calamares does some basic checking here to see if the system is usable for installation, and will warn you if something seems to be wrong. Having less than the shown disc space or available RAM will almost certainly fail the install.
You can change the language of the installer here. Over fifty languages are supported. There may be some buttons that link to your distribution’s website (for instance, so you can read the release notes).
Calamares checks if there is internet connectivity (this is used by many distributions for package functions) by loading a well-known page. This is configured by the distribution.