Dharma

I keep reading and hearing about Dharma and I think I know what it means (or should know) but am vague about it.
Here is a Wikipedia definition:

Dharma is to cultivate the knowledge and practice of laws and principles that hold together the fabric of reality, natural phenomena and personality of human beings in dynamic interdependence and harmony.

This definition is relatively simple and contains terms such as 'interdependence' and 'harmony' that I really like and know are important.
And further:

In order to attain wisdom one must understand the nature of things (the dharma) and part of the practice of Buddhism is the investigation of Nature...This means to adopt an objective, scientific approach to understanding the causal relationships between various phenomena. In particular it refers to the dispassionate self-observation discussed in teachings such as the Satipatthana Sutta, 'The Discourse on the Establishing of Mindfulness'.

Here is a simple definition by Pema Chodron in When things fall apart: heart advice for difficult times:

[Dharma] is total appreciation of impermanence and change.

I like it.