Battleground states, also known as swing states, are regions in the United States where both major political parties have similar levels of support among voters. These states can play a crucial role in determining the outcome of elections, as they are not consistently won by one party. Candidates often focus their campaigns on these areas to sway undecided voters. In presidential elections, battleground states can change from one election cycle to another, depending on various factors like demographics and political trends. Examples of battleground states include Florida, Pennsylvania, and Wisconsin. Winning these states can be essential for a candidate's success in the Electoral College.