RAM is usually measured in gigabytes. The more gigabytes of RAM a computer has, the more programs and operations it can handle at the same time.
Typical computers might have the following RAM:
Each unique memory location in RAM holds one word of information. Every memory location has a unique address so that once data has been stored there it can be found again later when it's needed. RAM also has a word size measured in bits to indicate the size of the memory locations.
The word size of the machine is how many bits its CPU can manipulate in one go.
The amount of data that a CPU can manipulate with one machine code instruction or transfer over a bus is measured in bits. When you look up the CPU specifications of any computer or games console, you will find out if it is a 32-bit, 64-bit or 128-bit machine.
A CPU with a 64-bit word size can process 64 bits using one single machine code instruction. This is twice as many bits as a 32-bit CPU.
Increasing the word size means more data can be manipulated at a greater speed. It also means that the CPU can keep track of a larger range of memory locations.
There are two types of RAM: dynamic RAM and static RAM.
DRAM is usually used for the main RAM memory. SRAM is used for cache memory. Static RAM is more complex to build and much more expensive than DRAM.