The dump1090 Program

Below is a short sample of text output of decoded ADS-B mode-S broadcast messages from the dump1090 program. Its output is a simple text rendering in a terminal or command line window.
The all important tracking information can be used to track any aircraft whose broadcasts can be received.

Unfortunately dump1090 is no longer maintained. However, there are plenty of other programs, some that are derivatives, that can be used to decode ADS-B data. Some can even display decoded aircraft data on maps in real time.

FlightAware dump1090-fa Program

One excellent ADS-B program is FlightAware's fork of the mutability dump1090 (also free and open-source) called dump1090-fa. They have greatly enhanced its capability and utility with the ability to do mapping. It even includes an HTTP server for the aircraft tracking maps.
FlightAware offers installers for Raspbian (Raspberry Pi OS), macOS and FreeBSD. An example of FlightAware's mapped data display is shown below:

DeepWiki's FlightAware dump1090 article provides a lot of in-depth information on the dump1090-fa software including excellent in-depth technical descriptions:
  🔗 DeepWiki - flightaware/dump1090