Linux Tweaks program- great to manipulate your desktop min. /max. button activation.

[ragnarok1968]

I have to admit, I already installed tweaks already so I'll go through the flow.

program: Gnome Tweaks (installed automatically.)

I opened a terminal window and threw the command at it;
apt search Gnome-Tweaks

and what you'll find in return...
Sorting... Done
Full Text Search... Done
gnome-shell-extension-caffeine/bionic,bionic 0~git20171229-2 all
GNOME Shell extension to keep your computer awake

gnome-shell-extension-mediaplayer/bionic,bionic 3.5-3 all
GNOME Shell extension to control media players

gnome-shell-extension-top-icons-plus/bionic,bionic 21-3 all
GNOME Shell extension to move system tray icons to top bar

gnome-tweaks/bionic,bionic,now 3.28.1-1 all [installed,automatic]
tool to adjust advanced configuration settings for GNOME
I highlighted gnome-tweaks green for the sake of this tutorial.

anyhow, I opened tweaks by going to "show applications" in the lower, left of the desktop. I noticed that there weren't any maximize/minimize
buttons on any of the windows from the default installation process, however, I enjoy as I like to do, extensive research in most cases and being able to min.max a window is crucial for me. But having left Microsoft's environment, I still enjoyed being able to min/max windows to go back and forth between ebooks, PDF files, research programs and LibreOffice Writer

so I go into Gnome Tweaks and navigate to the "Windows" section and at the bottom, simply toggle the switch buttons to on for a min. and max. buttons and they
should immediately appear after activation. I've included a screenshot of where to locate this feature.

Enjoy!

 

[ragnarok1968]

sigh... I meant this for anyone but more pointedly to newcomers to Ubuntu. sorry for the lack of clarification on that

 

[Neemobeer]

Gnome 3.X has never been very customizable. Gnome 2.X was way more customizable. You can also install Ubuntu-Tweak which is no longer actively developed but should still work in 18

 

[ragnarok1968]

actually, Ubuntu installed it automatically with the OS. I did a

apt search Gnome-tweaks

then the output in terminal had a [installed automatically] or something along those lines.
I wanted to install it from the terminal. It works amazingly well.