Window cleaning is the process of removing dirt, grime, smudges, and other contaminants from the glass surfaces of windows to make them clear and transparent. This can involve a variety of techniques and tools, depending on the size, location, and type of windows.

Basic steps in window cleaning include:

1. Preparation: Gather cleaning supplies such as a squeegee, bucket, window cleaning solution, microfiber cloths, and possibly a ladder if the windows are high up.
2. Dusting: Remove any dust or cobwebs from the window frame and sill.
3. Cleaning: Apply a cleaning solution to the glass. This can be a commercial window cleaner or a homemade mix of water and vinegar or dish soap.
4. Squeegeeing: Use a squeegee to remove the cleaning solution from the glass, typically starting from the top and working your way down in a consistent motion to avoid streaks.
5. Drying: Wipe down the edges and any remaining drips with a microfiber cloth to ensure a streak-free finish.

For larger or more complex windows, like those in high-rise buildings, professional window cleaners may use specialized equipment such as extension poles, water-fed poles, or even ropes and harnesses for safety.