Answer:
I assume you are asking for the examples in the world of politics.
1) A safe state, by its name, is a state that will almost 100% go to one political party. That is either Democratic or Republican. If a State almost leaned 100% to vote for a Democrat. Then it would be considered a safe state among democrats and democratic candidates. As well as Vice Versa.
2) A Swing State is a state that can go either way in an election between the two major parties. It is a State that can either go Republican or Democratic. These states are considered purple states. These states are very important for Presidential Candidates in securing a victory for an election. This is why Swing states can determine which side it chooses in an election. They are the main focus for Federal Government Politicians(Senators, Representatives, President.)
Hope this helps!