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Initially, you will only need to download and use the first image of a set (labelled as debian-something-1 to be able to start the Debian installer and set up Debian on your computer. If there are more images available here (labelled debian-something-2, debian-something-3, etc.), they contain the extra packages that can be installed on a Debian system (as mentioned previously). They will not be bootable and are entirely optional. If you have a fast Internet connection, you're most likely better off installing any desired extra packages directly from the Debian mirrors on the Internet instead of by using these extra images.
Isso significa que você deve usar debian-9.4.0-amd64-DVD-1.iso para instalar Debian . Também é uma boa ideia tentar executar o Debian em um ambiente virtual para testá-lo antes de substituir seu sistema operacional atual.