High ping means your data takes too long to reach the server, causing delays in audio and video. For calls, aim for ping under 100ms. To reduce it: switch to Ethernet — this alone can cut ping from 30-100ms (Wi-Fi) to 1-5ms. Disconnect VPN if not required — VPN routing adds 20-100ms depending on server distance. Close bandwidth-heavy apps that cause router queuing (bufferbloat). Restart your router. On Windows, run a ping test to Google's DNS: open Command Prompt and type "ping 8.8.8.8" — if latency is high even to Google, the issue is your ISP or router. If ping is only high on Wi-Fi, move closer to the router or use 5GHz. Enable QoS on your router to prioritize real-time traffic. If your ISP consistently delivers high latency (150ms+), consider switching providers. During important calls, ask others on your network to pause downloads and streaming.