for us non-americans, can someone please explain what general political aims the 'moderate' and 'progressive' parties represent? And where are they on the republican democrat spectrum?
It's pretty hard to say what the terms "progressive" and "moderate" mean in a US context, but I would say that both terms exclude the American far right and populist movements, and are vague as to what they include otherwise. The Overton window has shifted hard to the right in the United States, so it's probably somewhat right of what you may expect from, say, a European perspective. A moderate will probably be sympathetic to limiting immigration, for example, a progressive is likely more in support of immigration. Both groups probably support minority rights (e.g. LGBTQ, Muslim, etc), but moderates less so.
In terms of economics, both terms and parties generally describe liberal capitalist economic policy, which is dogmatically entrenched across the US political spectrum, to the point where most Americans cannot conceptualize economic systems other than liberal capitalism. The main difference in political economic values across the US political spectrum fixate mainly on who pays how much taxes, and subsidies for liberal capitalist businesses. Progressives may be more pro-union, whereas most moderates are generally not.
Moderate and progressive groups can overlap, particularly in a politician who wants to appeal to both, usually by contrasting themselves with the right.
Disclosing my biases: I am an American leftist (or social democrat, if you prefer) living abroad, and I generally have quite a lot of disdain for moderates, particularly in the United States. I'm definitely holding my punches for this comment, though, for what it's worth.
If you have a few minutes of thought to the ~200 countries that 8 billion people are living under, like China, India, Russia, Japan, Iran, Nigeria, Indonesia, Poland, Phillipines, Turkey, and their policies on immigration, LGBT, drug use, freedom of speech/press, you would quickly be disabused of any idea the US democrats are center-right.
What I think is that steeped in a Western European leftist bubble, 95% of the world is right wing to you, and you’re confused on where America stands in that spectrum, forgetting about who’s currently been elected in the rest of Europe like Sweden, UK, Poland, Netherlands, Italy, Hungary, Serbia, etc.
This requires a much longer thesis. In short, war throughout history is quite a centrist position (since it's been waged extensively by both left and rightists). Right now you have the Democrats advocating for defense of a nation against invasion, and a leftist government (Venezuela) advocating for the invasion and annexation of Guyana. When leftist governments aren't advocating for industrial military (USSR), global armed revolution and killing, it's usually said through the privilege and zero-skin-in-the-game safety of being under the US' defensive shield, or it's Pol Pot.
> Democrats is to preserve the status quo in all matters: social
Quite humorous to most global onlookers, I'm sure, as most would not be fond of some Democrats' constant push for "social justice."
> don't forget about Europe when establishing your list of countries to define a global overton window
Europe is 9.3% of the world. Half of which wouldn't agree with you since there are still many right wing governments in Europe and 41% of France voted for Le Pen.
So again, I'd recommend you'd be more accurate in relating the US to whichever country you're in, instead of making statements on the positions of people around the globe in which you seem naive on their governments and history.