What are the differences between a vacuum cleaner with a water filter and one with a HEPA filter?

A vacuum cleaner with a water filter uses water to trap dust and dirt particles, while a vacuum cleaner with a HEPA filter uses a high-efficiency particulate air filter to trap smaller particles like allergens and pollutants. Water filters are typically easier to clean but may not be as effective at trapping small particles as HEPA filters. HEPA filters are more efficient at removing allergens and pollutants from the air but may require more maintenance.