Bravely Second is a direct sequel in the same world with the same characters. Bravely Default 2 is a new game in the same franchise, not connected to the previous games.
Oh, okay so I don't need to play the old ones then. Good to know I can just start the new one. Now to wait for price drop since I don't trust the gameplay balance. o_o
I may try the new ram site, and download more RAM to my Switch. Not sure if ddr3 is the right ram
for it tho. Edit- no it uses floppy Ram, just like @AncientBoi