This is the output of a command like neofetch or fastfetch, which are two programs that give extensive info about a computer. You can configure these programs’ outputs as you wish.

The icon on the left usually represents the (Linux) distribution of the OS (I.e. Ubuntu, Debian, arch).
on the right, you get

• OS (Linux distribution, or flavour)
• Host, which is the machine’s name, it can be set by the user but it’s usually the laptop’s model, or motherboard I guess if on a big computer
• the kernel is the “core” of an os, which makes it able to use the CPU, GPU, keyboard, camera, etc
• uptime, or how long the computer has been awake since last boot
• packages tells you how many packages are installed; packages can be programs, libraries, or about anything, that you can install with a package manager which is, here, DPKG; flatpak can install packages in a more containerised, isolated way
• shell is the interpreter you use for commands in your terminal (fish, bash, zsh). Most are pretty similar
• resolution is the screen resolution
• DE is the desktop environment. It’s the thing that provides almost everything that’s not an app in a window, I.e. your desktop, notifications, etc. It can be Cinnamon, KDE Plasma, …
• WM is the window manager; it puts apps inside windows so that you can easily move them around
• wm theme, and theme are themes applied to the DE and WM that alter how the interface is looking like; you could probably make it copy window’s theme if you wanted
• Icons is the icon pack used for app icons Kalong with system icons like emojis, symbols (WiFi, battery), etc)
• terminal is the interface that lets you control your machine from a command line (it runs your shell inside which interprets commands)
• CPU is CPU
• GPU is GPU (one of them is integrated, the other is discrete (it will be used for extensive calculations only, I.e. games, but the DE and WM usually use the integrated one, unless you want otherwise)
• memory is ram
• and the colours at the end show you what the terminal will use when it is asked to print things in xyz color (to show errors, etc) (because yeah you can choose them)

Hope it’s a bit clearer lol, even tho I am far from knowing exactly what stuff is

P.S. i just noticed you did not ask for an everything explanation, sorry for the linux-splaining