How spatial resolution of a NWP model works?
Yes, the deterministic GFS model (one model) has higher spatial resolution than the GEFS models (31 models). That is, that the latitude and longitude of the entire world is incremented by 0.25° in the GFS and 0.5° in the GEFS (they upgraded both in the past two years). When people say &quot;high resolution,&quot; think of it like &quot;more pixels&quot; on a video (like 1080p).
On a more technical note, the GFS's (internal) resolution was once described as T-numbers, which counts the number of waves that can be fitted. The GFS could fit 1534 waves. However, since the upgrade in the dynamical core, the resolution has taken a different number. I don't exactly know the physical interpretation of the C-number, but the GEFS's C-number is currently C384 (my guess is that it is the number of cubes on one face of the cubed sphere).