Rather than providing the commercial reference of a computer or piece of hardware, it is usually better to directly ask the system to describe itself. On top of saving time to everyone, this also often provides more details, including something specific to the running system.
Below is a (not exhaustive) list of commands for retrieving system information.
If you don’t know how to use those commands, or how to provide them to support, see: [HowTo] Use the terminal / TTY
If you can’t access your system like usual, see: [HowTo] Reach a minimal system
Remember to use formatting when providing the result in the forum!
This is the main source of information to provide for support.
The commands below provide detailed information for specific cases.
mhwd -li mhwd -l
lsblk -fa LANG=C sudo parted -l
LANG=C df -h