ROS Install gone badly on Ubuntu 20.04

[flyingdutchman5564]

Updating ubuntu I get this on my Dell Precision 7510 laptop

kbest@kbest-Precision-7510:~$ sudo apt update
Hit:1 http://us.archive.ubuntu.com/ubuntu focal InRelease
Get:2 http://us.archive.ubuntu.com/ubuntu focal-updates InRelease [114 kB]
Get:3 http://us.archive.ubuntu.com/ubuntu focal-backports InRelease [108 kB]
Get:4 http://packages.ros.org/ros/ubuntu focal InRelease [4,679 B]
Hit:5 https://download.virtualbox.org/virtualbox/debian xenial InRelease
Hit:6 http://archive.canonical.com/ubuntu focal InRelease
Get:7 http://security.ubuntu.com/ubuntu focal-security InRelease [114 kB]
Hit:8 http://archive.ubuntu.com/ubuntu focal InRelease
Get:9 http://us.archive.ubuntu.com/ubuntu focal-updates/main Sources [528 kB]
Get:10 http://us.archive.ubuntu.com/ubuntu focal-updates/main amd64 Packages [2,196 kB]
Err:4 http://packages.ros.org/ros/ubuntu focal InRelease
The following signatures couldn't be verified because the public key is not available: NO_PUBKEY F42ED6FBAB17C654
Get:11 http://us.archive.ubuntu.com/ubuntu focal-updates/main i386 Packages [745 kB]
Get:12 http://us.archive.ubuntu.com/ubuntu focal-updates/main amd64 DEP-11 Metadata [274 kB]
Get:13 http://us.archive.ubuntu.com/ubuntu focal-updates/main amd64 c-n-f Metadata [16.0 kB]
Get:14 http://us.archive.ubuntu.com/ubuntu focal-updates/universe amd64 DEP-11 Metadata [405 kB]
Get:15 http://us.archive.ubuntu.com/ubuntu focal-updates/multiverse amd64 DEP-11 Metadata [940 B]
Get:16 http://us.archive.ubuntu.com/ubuntu focal-backports/main amd64 DEP-11 Metadata [8,024 B]
Get:17 http://us.archive.ubuntu.com/ubuntu focal-backports/universe amd64 DEP-11 Metadata [30.5 kB]
Get:18 http://security.ubuntu.com/ubuntu focal-security/main Sources [252 kB]
Get:19 http://security.ubuntu.com/ubuntu focal-security/main amd64 Packages [1,821 kB]
Get:20 http://security.ubuntu.com/ubuntu focal-security/main amd64 DEP-11 Metadata [40.7 kB]
Get:21 http://security.ubuntu.com/ubuntu focal-security/main amd64 c-n-f Metadata [11.2 kB]
Get:22 http://security.ubuntu.com/ubuntu focal-security/universe amd64 DEP-11 Metadata [92.9 kB]
Get:23 http://security.ubuntu.com/ubuntu focal-security/multiverse amd64 DEP-11 Metadata [2,468 B]
Reading package lists... Done
W: GPG error: http://packages.ros.org/ros/ubuntu focal InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY F42ED6FBAB17C654
E: The repository 'http://packages.ros.org/ros/ubuntu focal InRelease' is not signed.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.

 

[KGIII]

And what is "ROS"?

 

[Condobloke]

? Robot Operating System ?