# dpkg
# Package manager for Debian

# Display the package(s) in which the given file would be found. This is very
# useful, because it lets you know to which package a file belongs.
dpkg -S /usr/bin/awk

# Where FILE is the provided Debian package to install, so instructed by `-i`.
dpkg -i [FILE]

# List Debian packages currently installed.
dpkg --get-selections

# List Debian packages installed and in other states, such as not-yet-purged.
dpkg -l