Praxis is an overloaded term whose generic meaning can be action.
We can locate its origin in Aristotle, tacking into account the distinction between episteme and techne, where "epistêmê is the Greek word most often translated as knowledge, while technê is translated as either craft or art."
For Aristotle:
There are five virtues of thought: technê, epistêmê, phronêsis, sophia, and nous. [...] The two virtues of thought that deal with what can be otherwise, i.e., what is contingent, are technê and phronêsis, craft and practical wisdom. Aristotle emphasizes the former, a disposition with respect to making (poiêsis), is distinct from the latter, a disposition with respect to doing (praxis). [...] By contrast, practical wisdom does not make something separate the way craft does. Its province is doing (praxis) and not making (poiêsis).The distinction is between activity, whose end is in itself, and making, whose end is a product separate from the activity of making.
"When someone plays the flute, e.g., typically there is no further product of playing; playing the flute is an end in itself. However, when one makes a house, e.g., the activity of making a house is not an end in itself but has a product, which is separate from the activity."
It can be worth noting that for Aristotle scientific knowledge (epistêmê) can be viewed as a sort of praxis [doing], because it is aimed at satisfying our (human) desire to understand. Thus, scientific knowledge has an "end in itself", while the modern view of science as strictly related to technical applications consider scientific knowledge as "making".
See e.g. Michael Bowler, Heidegger and Aristotle: Philosophy as Praxis (Continuum, 2008), page 105: "we can see how the scientific comportment is a praxis, i.e. an activity whose for-the-sake-of-which is that very activity."
Jumping now to more current usage, "Praxis is the process by which a theory, lesson, or skill is enacted, embodied, realized, applied, or put into practice. "Praxis" may also refer to the act of engaging, applying, exercising, realizing, or practising ideas. This has been a recurrent topic in the field of philosophy, discussed in the writings of Plato, Aristotle, St. Augustine, Francis Bacon, Immanuel Kant, Søren Kierkegaard, Ludwig von Mises, Karl Marx, Antonio Gramsci, Martin Heidegger, Hannah Arendt, Jean-Paul Sartre, and many others."
The use of praxis in the context e.g. of political action (in a broad sense, like environmental issues) seems to reverse original A's thought: political action is a kind of making (poiêsis), because is not an activity whose end is in itself (like playing the flute), but is an activity aimed at producing a result.
Compare with Wiki's Praxis:Origins: "Aristotle further divided the knowledge derived from praxis into ethics, economics, and politics".