On the side where I bought my laptop there was 8 GB DDR memory. But I found that only 6 Gb are available. I found that surprising because my old laptop (also bought on the same page) had also given 8 GB and really 8 GB available. The only differences from my old and new laptops is that the new better GPU and CPU has a 512 Gb SSD and the old one only a 256 Gb SSD. Should I buy a new laptop and hope that it really has 8GB RAM?
Perhaps, the PC runs via APU, which is assigned 2 GB of your 8 GB.
Is it a dedicated GPU or an iGPU? Then the "graphics card memory" is probably reserved by the main memory.
Since you do not provide any information about the notebook, one can only assume.
Your internal iGPU takes up 2GB of RAM, you may be able to change this in the BIOS.