comfort zone
ˈcomfort zone 7 [comfort zone] noun
1. (sometimes disapproving) a place or situation in which you feel safe or comfortable, especially when you choose to stay in this situation instead of trying to work harder or achieve more
• Stepping outside your comfort zone and trying new things can be a great experience.
• We cannot afford to have anyone operating in a comfort zone.
• I'll tell you what drives me crazy— people who have talent but cruise along in the comfort zone.
2. (approving) (especially in sport) a state in which you feel confident and are performing at your best
• I knew if I could find my comfort zone I would be difficult to beat.