Not able to install any apps with command apt-get install

I have recently installed Debian 8 (Jessie) and when I try to install an app, the message:

A media change is required. Please insert the disc labeled ‘Debian GNU/Linux 8.7.1_Jessie_-Official amd64 DVD Binary – 1 20170116-11:01’ to continue

appears to me and I can’t install anything.

I have made the change in /etc/apt/sources.list, but it is still not repaired:

Apparently your system tries to install software from a CD-ROM / DVD instead of the Internet.

You need to edit your /etc/apt/sources.list file (use sudo; the file is only writable by super users) and comment out the cdrom entry by prefixing it with a #.

Make sure your file contains the respective entries needed for your distribution, which you can check here: https://debgen.simplylinux.ch/

Save the file, then run apt-get update and you should be good.