Window cleaning involves removing dirt, dust, and grime from both the interior and exterior surfaces of windows. For a thorough clean, start with downstairs windows. Use a squeegee and a mixture of water and dish soap to wipe the glass clean. Make sure to remove any excess water or streaks. Next, move upstairs, where safety is crucial. Use a sturdy ladder or extendable pole to reach higher windows. Repeat the same process, ensuring no smudges remain. For exterior cleaning, consider using a pressure washer or hire a professional for a more efficient and safer job.