apt-cache

Debian and Ubuntu package query tool. More information: https://manpages.debian.org/latest/apt/apt-cache.8.html.

• Search for a package in your current sources:
  apt-cache search {{query}}
• Show information about a package:
  apt-cache show {{package}}
• Show whether a package is installed and up to date:
  apt-cache policy {{package}}
• Show dependencies for a package:
  apt-cache depends {{package}}
• Show packages that depend on a particular package:
  apt-cache rdepends {{package}}