First Minister Nicola Sturgeon, who is in charge of the government in Scotland, has announced that she plans to ask the UK government for permission to hold another referendum in Scotland
This will allow adults to decide whether or not they want Scotland to be a part of the UK.
She has said that she wants this referendum to happen between Autumn 2018 and Spring 2019.
Scotland has had a referendum about this issue before, in September 2014.
So why is Nicola Sturgeon saying that she wants another one?
Read below to find out more about what has happened.
What happened in September 2014?
The UK is made up of four countries - Scotland, Wales, Northern Ireland and England.
Two and a half years ago, adults in Scotland were asked to choose whether or not they wanted Scotland to remain a part of the UK.
They were asked 'Should Scotland be an independent country?' and voters chose yes or no.
Just over half (55.3%) voted no, so Scotland remains part of the UK.
What has happened now?
You might remember that last year, there was a different referendum for the whole of the UK.
The result of this referendum was that UK adults voted to leave a group of countries called the European Union (EU).
When all of the UK's votes were added together, more adults voted to leave the EU than to stay in it.
However, if Scotland's votes were counted on their own, more adults in Scotland wanted to stay in the EU than wanted to leave it.
In fact, just over 3 in 5 Scottish adults wanted the UK to stay part of the EU.
Given that it is expected the UK - including Scotland - will soon be on its way out of the EU, Ms Sturgeon says that Scottish people should get to decide again whether they want to be a part of the UK or become an independent country - and, importantly, get to make its own decisions about this sort of thing.
Not all politicians in Scotland agree that another referendum should take place though.
Why does Ms Sturgeon want to do this now?
The official two-year process for the UK to leave the EU is expected to begin soon.
So Ms Sturgeon wants another referendum to be held between Autumn 2018 and Spring 2019.
This is because it is thought it will be more clear by then how Brexit will work - and, importantly, how it might affect Scotland.
Ms Sturgeon thinks Scottish people will have more information to help them make that decision by then.
So what happens next?
Ms Sturgeon does not have the power to make another referendum happen by herself.
She needs to get a special type of agreement from UK Prime Minister Theresa May to allow her to have one.
It has not been confirmed whether or not the UK government will give this to her.
It has said that a second referendum would be "divisive" and would "cause huge economic uncertainty at the worst possible time", but it has not said that it would refuse permission for it to happen.
First, though, Ms Sturgeon needs to get the support of the Scottish parliament.
She has said: "I will take the steps necessary now to make sure that Scotland will have a choice at the end of this [Brexit] process."
Even if the UK government agrees that another referendum can take place, it is not clear when it will be or how it will be carried out, as that would need to be decided too.
If Scotland did vote to become independent, would it get to stay in the EU?
A situation like Brexit has not happened before, so we do not know what will happen or how it would work.
It is not as simple as Scotland being able to keep the UK's membership, while the rest of the UK leaves.
What would happen between Scotland and the EU, if the country were able to vote to become independent before the Brexit process has been finished, remains to be seen.