dpkg

Lock a version of a package

echo "PKG_NAME hold" | dpkg --set-selections

Release the lock

echo "<package-name> install" | sudo dpkg --set-selections

See the current selections

dpkg --get-selections

apt

Lock a version

sudo apt-mark hold <package-name>

Remove the hold

sudo apt-mark unhold <package-name>

Look at info for a package

apt show <package-name>

Find the files provided by a package

dpkg -L PACKAGE

Upgrade one package

apt-get install --only-upgrade <packagename>

Find available versions

apt-cache policy PACKAGE_NAME