Steam cleaning, also known as hot water extraction, is a popular method of cleaning carpets and upholstery. It involves using a machine to inject a solution of hot water and cleaning agent into the carpet, and then using high pressure to extract the dirt and moisture from the carpet.

Here is a step-by-step guide on how steam cleaning works:

1. Vacuum the carpet: Before steam cleaning, it is important to thoroughly vacuum the carpet to remove any loose dirt and debris. This will help to ensure that the steam cleaning solution can effectively penetrate the carpet fibers and remove embedded dirt.
2. Pre-treat stains and heavily soiled areas: If the carpet has stains or heavily soiled areas, it may be necessary to pre-treat these areas with a spotting solution or a pre-spray. This will help to loosen and lift the dirt from the carpet fibers, making it easier to remove during the steam cleaning process.
3. Apply the cleaning solution: The steam cleaning machine uses a pressurized hose to inject a solution of hot water and cleaning agent into the carpet. The solution is designed to penetrate the carpet fibers and loosen dirt and grime.
4. Extract the dirt and moisture: After the cleaning solution has had time to work, the machine uses high pressure to extract the dirt and moisture from the carpet. The machine has a powerful suction that removes the dirt and cleaning solution, leaving the carpet clean and almost dry.
5. Dry the carpet: After the cleaning process is complete, the carpet will need to dry completely before it can be used. The drying time will depend on the humidity and ventilation in the room, as well as the type of cleaning solution used. It is generally recommended to avoid walking on the carpet or replacing furniture until it is completely dry.

Overall, steam cleaning is a highly effective method of cleaning carpets and upholstery. It uses a combination of hot water, cleaning solution, and high pressure to remove dirt and grime from the carpet fibers, leaving the carpet clean and almost dry.