What does the word cap mean?

Question

In this article: https://edition.cnn.com/travel/article/australians-stuck-abroad-covid/index.html
the word CAP is present, what does it mean?

Example:

Sunday marked two months since Prime Minister Scott Morrison introduced cap of just 4,000 international arrivals per week.

So what did the sentence say?

The citizen of Australia came back is by amount of 4,000 people

or:

The possible amount of people that their are citizen of Australia is 4,000 can be allow to came, so the overhead of people is 4,000.

Can somebody help me?

Answer 1

Sunday marked two months since Prime Minister Scott Morrison introduced cap of just 4,000 international arrivals per week.

In this sentence Cap means that the maximum international arrivals per week in Australia are 4,000.

But CAP can mean a lot of things and it can also take on connotations related to slang or urban speaking.

Cambridge: Cambridge dictionary for CAP