Hello Clemmy.
The initial RAM of this model is onboard, but there is an extra slot for you to upgrade up to 8GB.
And the hard disk, there is a M.2 2280 SATA3/PCIe slot supporting up to 512GB.
If your device is sold with dual disk initially, then the 2.5inch 7mm SATA3 hard disk is also replaceable,
but if the device is sold with only SSD, then only the M.2 SSD can be installed.
Thank you.