The brains inside the computer.  The CPU (central processing unit) is responsible for executing all in the instructions demanded within the PC. The more powerful the CPU, the better it can decode those instructions. More cores (and threads) means that the CPU can handle more processes at the same time. The faster the clock speed, the faster instructions are carried around the computer.

Cores: Each CPU core can execute a set of instructions. The more cores the CPU has, the more simultaneous instructions your PC can execute at at the same time

Threads: Cores on a CPU can be virtually split to process even more instructions (hyper threading).

Clock Speed: The higher the clock speed, the faster the CPU can process instructions. CPUs usually have 2 speeds as their clock speeds can throttle, so it can be slower when the PC is idle to save energy.

Memory or RAM (random access memory) is temporary (it erases on restart or shut down) and fast accessed storage with the PC. Every program that gets loaded up (including windows) when you click on a program gets (mostly) loaded into RAM. That allows the PC to quickly access those instructions. The faster the RAM, the quicker your PC can access the information needed to display on the screen. The more RAM that you have, the more that can be loaded for fast access without having to go back to the hard drive to grab the data that is needed.

Which Memory is right for me?

Memory Type: DDR4 or DDR5? DDR5 supports a higher frequency and therefore higher speed.

Speed: Measured in MHz, it is the amount of the times the ram can read/werite in a second. 

Size: A basic answer is the Sim Racing games wont use more than 16GB, but if you are running other applications as well (streaming, dashboards, etc) 32GB is safer and faster.

Your hard drive or SSD (solid state drives) is where all your programs and data are stored. The larger the drive size, the more that can be permanently (given that you don’t delete it) written to the it. Speed is an important factor for hard drives. The older type drives read around 200MBps (megabytes per second). Then came the SSD (solid state drive, no moving parts) which read around 500 MBps. The newer NVME M.2 drives are much smaller and can read data at a transfer rate of 7,450 MBps. 

Max Read: The maximum speeds that data is read from the the hard drive.

Max Write: The maximum speed that data is written to the hard drive (stored).

Terabytes Written (TBW) & MTBF: The life span of the hard drive in terms of terabytes written to it or hours used.

Even though processors and motherboards have embedded graphics, without using a dedicated graphics card, your racing simulator might look like playing an Atari game from 1982. By using a discreet graphics cards, your simulation can be almost indistinguishable from the real thing. Graphics cards have their own GPU or graphical processing units and similar to the CPU, a more powerful GPU will render a fast moving image with greater detail and fluidity.

CUDA Cores: Parallel processors within the Nvidia processor. More CUDA cores will means more raw computing power from the GPU.

Memory: GPU RAM stores graphics data so that the GPU can access it allowing you to see visuals on your computer screen.Me