Hey there!
Ergonomics is the design and arrangement of things to maximize safety while in use. When used in the workplace, ergonomics can prevent injuries related to work (headaches, eye strain, muscle aches, etc.) which also maximizes on productivity in addition to safety. Basic workplace ergonomics includes having good posture, keeping elbows and knees bent at 90°, placing a computer monitor 20–40 inches away from eyes, and taking breaks.
Hope this helped you out! :-)