Ubuntu, a GNU/Linux distribution based on Debian, uses Apt package manager to install, uninstall and update applications and their requirements.
During the installation process, Apt by default keeps downloaded packages on the file system. It can use a lot of disk space so I recommend to occasionally clean the software cache on your Ubuntu system.
Deleting Apt cache using file manager
1) Run file manager (e.g. Nautilus) as root user
2) Navitage to /var/cache/apt/archives
3) Delete all .deb installation package files
Note: Be sure not to delete folder partial and file lock.
Deleting Apt cache with command line
Removing downloaded packages (.deb) that are already installed and no longer needed:
sudo apt-get clean
Deleting all archives in the cache for packages that can not be downloaded anymore (e.g. packages not present in the repository):
sudo apt-get autoclean
Removing unnecessary packages, for example after uninstalling an application there could be packages you don’t need anymore:
Deleting old kernel versions:
sudo apt-get remove --purge linux-image-X.X.XX-XX-generic
But if you’re not sure which kernel version to delete:
dpkg --get-selections | grep linux-image