The condition is a boolean expression that the loop evaluates before each iteration. The loop runs as long as the condition evaluates to true. When it becomes false, the loop stops. You can use comparisons like i < 10, count != 0, or x >= limit.
You can also combine checks with logical operators: i < 10 && x > 0. The condition is checked before each iteration, including the first. If the condition is false initially, the loop body never runs and execution skips to the next statement.