Is there a difference between understanding and describing? We describe something in order to make it intelligible.

However, do you think that we have "understood" nature itself? Or just describing nature but not understand it? Why or why not? — The0warrior

We have created the properly tools to describe what is around us. Physics help us to understand the nature and establish principles that supposed to be universals as you said, gravity.
But no, we do not have understand it at all yet. Nature itself is very complex. Probably we have to start with the roots and explain what is going on with Big Bang theory. It appears it is just a theory but involves the born of the earth. So while we cannot prove “specific” about the Big Bang theory we cannot understand the nature itself. We still have some realities which escapes from or view.

Do you agree with the following sentence: "the end of science is theology"? — The0warrior

No. Science is literally a weapon to fight against theology.

Probably describing nature. Or a version of it that fits our mode of cognition. "Understanding" is a very complex term and it's not entirely clear what it means. You can raise your arm, like anyone else. Do you understand how you do it? Some say yes, clearly I do understand it, I just raise my arm. Other may say I have no clue how I do it. I fall into the latter camp.

As for the theology question, no. Theology covers needs for many people that can't be covered by what physics says, in terms of karma or heaven or meaning. Maybe a subset of scientists find the mystical in science, but I'm not sure many people have that sensibility.

No. Science is literally a weapon to fight against theology. — javi2541997

Preconceived notions invalidate

Preconceived notions invalidate

We do not have anything preconceived. It all comes from experience and learnings (empiricism)
There is not nothing innate

Like we describe how gravity works but not understand why it is like that.

We have mathematical rules (...) to describe many events (...). However, do you think that we have "understood" nature itself? — The0warrior

Nature itself, no. Since Hume, understanding events as parts of a whole, does not necessarily grant understanding of the whole. Technically, knowledge, but one follows from the other so.....

do you think we have a way to finally "understand" it? — The0warrior

Non-sensical query. What would it look like if it turns out we never did?

Do you agree with the following sentence: "the end of science is theology"? — The0warrior

No. The end of science implies, on the one hand, complete empirical knowledge, and on the other, the impossibility of complete empirical knowledge. Neither necessarily implies theology, which has its ground in rational knowledge alone.

Interesting topic.

Welcome to TPF.

1. We have mathematical rules like F=ma, Maxwell equations, Standard model, general relativity to describe many events happening. However, do you think that we have "understood" nature itself? Or just describing nature but not understand it? Why or why not? — The0warrior

I think the question is misplaced, or poorly formulated; understanding pertains to scientific theories – the degree of causal depth, or computation complexity, their explanatory hypotheses contain – and not directly to "nature itself". And the degree to which scientific theories are used to predict unforeseen aspects of nature (potentially revising, extending or replacing current theories) is the degree to which they're understood.

2. If you think that we haven't underst[oo]d nature, do you think we have a way to finally "understand" it? In what way?

All scientific theories are approximations, and therefore fallibilistic. More accurate, or explanatory, approximations are always possible. 'Progress' is asymptotic, IMO never "final".

3. Do you agree with the following sentence: "the end of science is theology"?

On the contrary, theology haunts, or plays make-believe (i.e. woo-woo appeals to ignorance) in, the gaps of science.

Like we describe how gravity works but not understand why it is like that. — The0warrior

To describe gravity is to make it more intelligible - to understand it. In describing it we acquire an understanding of some of the whys and the hows.

It is a mistake to think of understanding as some unique final state of knowledge, so that we will understand the world only when we attain that state of knowledge, and until then we "do not have understand it at all," as @javi2541997 put it. There are many valid degrees and ways of understanding. It depends not only on what we can, but on what we want to know.

Speaking of physics, there are many subjects within this discipline, and each can have a number of theories and approaches and techniques, and each of those brings its own understanding of its subject. Again, it is a mistake to think that only a hypothetical "theory of everything" (TOE) can bring true understanding of the workings of the universe. We already understand a lot from all the descriptions/theories that we have. A TOE, if such is even possible in principle (and that is an open question), would add another layer of understanding, but it wouldn't subsume the understanding brought to us by other theories. (Note that I said a TOE, not the TOE, because it doesn't even have to be unique.)