5S is a systematic and disciplined approach to maintaining a clean, organized, and safe workplace. It is based on five Japanese words: Seiri (Sort), Seiton (Set in Order), Seiso (Shine), Seiketsu (Standardize), and Shitsuke (Sustain). The five steps of 5S are:

1. Sort: Remove unnecessary items from the workplace.
2. Set in Order: Organize the remaining items so they are easy to find and use.
3. Shine: Clean the workplace thoroughly.
4. Standardize: Establish procedures and guidelines for maintaining the first three steps.
5. Sustain: Continuously maintain the first four steps to ensure they become a habit.

Some companies also include a sixth "S" for safety, making it 6S. The safety step involves focusing on what can be done to eliminate risks in work processes by arranging things in certain ways. 5S can help improve safety in the workplace by identifying and eliminating various types of waste, improving overall efficiency, and reducing the risk of accidents.