They are completely different. Obamacare has nothing do with universal healthcare in the UK sense, but is a complex system of mandates that dictates how private health insurance is bought and sold.
Very simply there are three key parts:
1) everybody (who doesn't for qualify other government programs) now has to have private health insurance that covers certain things. If they don't get this from their employer, they're responsible for buying it themselves.
2) The government sets minimum standards as to what insurance companies have to cover and regulate what premiums they can charge for this coverage. They also forbid insurance companies from denying people coverage due to pre-existing condition.
3) To make sure that people can afford these mandatory insurance policies, they offer heavy subsidies to people who earn less than a certain limit.
In their attempts to lock in parts of the law so that an incoming shift of government couldn't easily change or repeal it, the Democrats hardcoded idiocies like a fixed date for the launch of the healthcare.gov website and features it had to have while leaving funding and development of the site a bit up in the air.
In a nominally functioning government, the ACA would have been a broad, general law laying out specific goals, requirements and mandates for compliance, delegating implementation and enforcement to a new or existing agency. But in the "regulations are bad, laws are good" environment in DC, processes and requirements which should have been regulations (which can be drawn up and vetted by a bureacracy under legislative supervision) ended up being in the actual law, which can only be changed by Congress and the President working together, which all but stopped after the 2010 midterm elections.
Add in the the Federal government is limited (by design) in what it can mandate individual States can do and you have this mess called Obamacare.
I don't support repealing it, I do support modifying it to make implementation more flexible, but that is almost certainly not going to happen under a Republican government.
There's an income tax penalty for each month you're uninsured, which eats into your tax returns. Last I checked, this penalty is still cheaper than actually paying for insurance.
Congress basically looked at the healthcare systems in Canada and Europe, looked at the existing healthcare system, took all the worst parts of both, and squished them together to make ObamaCare. Conservatives hate it because it's big government in action. Liberals hate it because it does absolutely nothing to fix the undue burden on individuals to pay for their own healthcare. It's a lose-lose proposition.
So basically, the US government system doesn't care about its populous at all, regardless who sits in the big chair?
the affordable care act is far from perfect, but it's also not useless in any sense, and it needs to be modified not repealed. And yes I'm partially saying that because I and my brother will both lose and not be able to afford health insurance if it is repealed. I'm also saying that because I strongly belief in the benefits that have come out of the bill, even at the cost of some major downsides.
It also includes mandatory purchasing of health insurance, which (while necessary to make a fully private system work) is philosophically objectionable to most people.
(The NHS is a fully state owned system that nonetheless has an internal market, which some commentators have called "playing at shops".)
This is not true. Obamacare included a very large expansion of 'medicaid' which is more like single payer healthcare, i.e. 'government paid for / free healthcare'.
The US actually has a single-payer health care system, called Medicare, for people 65 and older. It's wildly popular with the people who benefit from it, of both parties. It seems to be pretty well-run and to exert at least some useful downward pressure on costs. Extending it to all citizens doesn't seem like that big a leap to me. Of course it would all but obliterate the existing insurance industry, which has bought itself a lot of Congresscritters.
I think it would be a fascinating and hilarious irony if Trump came out supporting single-payer in the form of universal Medicare. I think the argument for having a single risk pool is very strong. And I don't see any other solution to the interlocking problems of containing costs (which are way out of hand here) and getting everyone insured.
Trump (whom I voted against, BTW) has shown he's not afraid to go against the Republican establishment. I think when he really looks at this problem he may come to this conclusion.