GNU Octave (or Octave herein) is a high-level language primarily intended for numerical computations, to solve linear, nonlinear, differential equations, to analyze statistical data, and to perform other numerical experiments with a good compatibility with Matlab. It has a variety of graphical capabilities, and can be extended through programs written in its own programming language.

To learn Octave is useful to solve complex equations and analyze data, and this website offers step-by-step tutorials for learning journey.

Also, if you want to learn Octave in 1hr 30min, you can also watch YouTube video below.