The nc package contains Netcat (the program is actually nc), a simple
utility for reading and writing data across network connections, using
the TCP or UDP protocols. Netcat is intended to be a reliable back-end
tool which can be used directly or easily driven by other programs and
scripts. Netcat is also a feature-rich network debugging and
exploration tool, since it can create many different connections and
has many built-in capabilities.

You may want to install the netcat package if you are administering a
network and you'd like to use its debugging and network exploration
capabilities.