Top number: current FPS
Higher number: smoother gameplay
Lower number: less smooth gameplay
Stable number: consistent performance
Big drops: stuttering or performance issues
1% low: worst short-term frame rate
1% low: rare severe frame drops
Frame time: time each frame takes to render
Lower frame time: better smoothness
Higher frame time: more lag or stutter
GPU usage: how hard the graphics card is working
CPU usage: how hard the processor is working
VRAM usage: graphics memory used
RAM usage: system memory used
Ping: network delay
Packet loss: lost network data
Red or yellow spikes: performance or connection problems