G-sync Monitors

Gents

I recently looked at LG 27GL650F-B to buy because i need G-Sync compatible monitor so that when my new rig comes with a RTX 2060 i had a monitor that can have quick refresh rate. However the retailer said that this monitor has no G-sync module. But is g-sync compatible, what the hell does that mean?

Will it actually work in sync with my RTX 2060 or not?

for info, I am buying a Ryzen 9 3600, 16gb 3000mhz ram, X570 MB, RTX 2060 with some other extras. its expensive so i need a monitor that worked well with teh unit.

because the retailer said it didnt have a g-sync module i went for this monitor instead ASUS VG278Q. Does this have a g-sync module? how can i determine myself if a G-Sync compatible monitor has a module? Or doe sit need a module and i am just worrying about nothing?

Thank you