In the context of U.S. elections, a swing state refers to a state where both major political parties have similar levels of support among voters, making it a critical focus during campaigns. Unlike solidly red (Republican) or blue (Democratic) states, swing states can shift between parties in different electoral cycles, often determining the outcome of presidential elections. Candidates invest significant time and resources in swing states, aiming to sway undecided voters. The dynamic nature of these states underscores their importance in the national electoral landscape.