Can't setup WiFi in Debian after reinstalling system despite following all the instructions given on Debian's website and associated manuals

Question

WiFi isn't working on Debian 8.7.1 on my HP laptop, with KDE. Posting this from mobile, hence, lack of formatting.

The plasma -nm applet is showing it just isn't displaying my WiFi network under any condition, despite the network not being hidden. Do I need to edit the /etc/network/interfaces file? (Given below) I know some programming and very little networking, hence, I can't figure out where I am going wrong. All the drivers required are present as verified by
apt-get install firmware-realtek

My home WiFi connection is ADSL router with WPA2 password.

My /etc/network/interfaces file is - auto l0 iface l0 inet loopback

auto eth0 iface eth0 inet dhcp

Answer 1

Debian is not recognizing your wifi interface and it's unable to load the appropiate drivers for your hardware.

Use the commands lspci and lsusb to find the hardware of your wifi interface.

The next step is to find and install the drivers related to your hardware.