I've serched a bit before posting, but i've not found a definitive answer...
I'm writing a webserver page that have a lot of pages and strings, and i'm trying to find all the ways to save some memory.
So, i've came across the PROGMEM and F(), from what i've undertood this functions must use the data in flash, reading it at runtime (with a bit of slowness due to the slow reading performance of flash), but the arduino reference site:
Store data in flash (program) memory instead of SRAM.
What that mean? At the time of compile the strings are already in flash, and at code execution are loaded into ram. PROGMEM and F() must avoid the load to SRAM phase, not Storing it to flash, as it's a thing that is already in flash.
Or i'm missing something?