Brute Force Running Time describes an algorithm which checks every possible combination of inputs to find an output.
Usually O(N) squared or worse time complexity.
Example:
int[] array = new int[]{0, 1, 2, ...};
for (int i = 0; i < array.length; i++)
for (jnt j = 0; j < array.length; j++)
if (condition(array[i], array[j]))
doThing();