Hi and welcome to the Linux club.

If you installed packages by commands like $ sudo apt install package, you can always check your commands history by:
$ less ~/.bash_history

So if you wanna remove package, just type:
$ sudo apt remove package, OR
$ sudo apt purge package (this will do a clean remove by also removing config files)

If you wanna use GUI, there is Synaptic. Basically it's just a front end to the CLI. You can install it by:
$ sudo apt install synaptic

You can also use commands to find any installed package and decide whether you want to remove it or not:
$ dpkg -l | grep -i package, OR
$ apt list --installed | grep -i package
*replace the word "package" to anything you're looking for

This post has been edited by Kadaj: Dec 2 2025, 10:19 AM

We typically install packages by using system package managers like apt, dnf, pacman or etc. If you install by compiling from source code yourselves, you'll know it very clearly coz it's much more complicated than just typing $ sudo apt install package.

There is another way to check it.
If you wanna know if a package called firefox is installed by system package managers or not, you can run the command like $ apt list firefox OR even $ sudo apt remove firefox.
If the package manager doesn't show it's installed or it can't manage the package, then you can check snap, flatpak and appimage.
If none of the package manager is managing the package, then you can question where did the package come from.
Don't worry about it.

If somehow you want to keep the system clean, just reinstall the system.
It only takes 10-15 mins to set up a new system.