Most states consistently vote red or blue, like 38 states that voted for the same party over and over again between 2000 and 2016, or they visibly lean overwhelmingly in the lead-up to the election. But then there are states that distance or poll very closely, which makes them less predictable and puts them in the category of swing states or battleground states.

There has been a lot of attention on Pennsylvania because its 19 electoral votes could remain blue and go to Vice President Kamala Harris or go back to former President Donald Trump. The state helped President Joe Biden win the 2020 election after he voted for Trump in 2016.

Here’s an overview of what a swing state is, who the swing states are, and why they are important.