It has 16GB of on-board flash behind a flash/SATA interface chip, basically a 16GB SSD as parts on the board (more compact and cheaper than a replaceable 2.5" d

It has 16GB of on-board flash behind a flash/SATA interface chip, basically a 16GB SSD as parts on the board (more compact and cheaper than a replaceable 2.5" drive). That is plenty big for the OS, lots of programs, and your home directory as long as you don't go overboard with pictures and videos. Those should go "in the cloud" or on a SD card.