For -E and -F, slightly different specs, e.g. M2 slots (5 vs 4) or their PCIe version support, or USB front panel connections. Power stages (VRM, capacitors) are also slightly different - these are shown in the product detail page on asus.com. -P is not 'ROG', so further different, including design (it's white/silver). There is now a II model for -E and -F, with support for Intel 14th gen, which seem more similar between themselves though...
-F and -E compared:
https://rog.asus.com/ch-en/compareresult?productline=motherboards&webpathname=ROG-STRIX-Z790-E-GAMING-WIFI-II,ROG-STRIX-Z790-F-GAMING-WIFI-II,ROG-STRIX-Z790-F-GAMING-WIFI,ROG-STRIX-Z790-E-GAMING-WIFI&partno=226979,226809,205836,205970&productid=24319,24320,21111,21117,
-P
https://www.asus.com/ch-en/motherboards-components/motherboards/prime/prime-z790-p/