Computer RAM (random access memory) holds the data for the CPU, typically loaded from hard disks or read from keyboard.
Find out your memory configuration
To find out how much RAM you have, enter
# hwinfo --memory 01: None 00.0: 10102 Main Memory [Created at memory.59] Unique ID: rdCR.CxwsZFjVASF Hardware Class: memory Model: "Main Memory" Memory Range: 0x00000000-0xc7fffffff (rw) Memory Size: 50 GB Config Status: cfg=new, avail=yes, need=no, active=unknown
In this case you have 50 GB of memory.
To find out what dimms you have, use
# dmidecode | less Memory Device Array Handle: 0x1000 Error Information Handle: Not Provided Total Width: 72 bits Data Width: 64 bits Size: 4096 MB Form Factor: DIMM