Threading is not a difficult idea to understand and I will present you with a simple analogy. Imagine that you are tasked with writing the numbers one to one hundred on a piece of paper. But you have to do it three times. Assuming you are not ambidextrous, you will write the numbers one to hundred once, then do it again, and then a final time. One after the other. But if humans had the ability to thread like a computer, then you would not have to write one to one hundred back to back to back, but rather simultaneously or in parallel.
This was an extremely important development in computer science, as it increased the potential processing speed of computers enormously. Think about how many processes a computer does every second. It must run all your background software, like antivirus and music streaming programs, while also updating every single pixel on your monitor when an input is made, while also checking for any updates, while also responding to any kind of user input, etc. There are potentially a ton of tasks that a computer is handling per second, and this is all only possible because of threading.
In particular, I’m speaking about the implementation of multi-threading in many modern computer systems. Single-threading is when a processor can only perform one single task at a time (like how you can only write one to one hundred once at at time) and multi-threading is where processes can be performed at the exact same moment by one processor.
Not only are CPUs able to process multiple threads at once, but they are also able to house multiple cores. These are called multi-core processors. So essentially, instead of having one processor that can multi-thread and process hundreds of tasks at once, there can be 2 or 4 or even more processors that all are making use of multi-threading all at the same time. So, a multi-core processor can greatly increase the processing power of a machine.
Individual computer tasks are actually amazing simple. However, in order to do very complex things, like simulate an open world in a game, there needs to be many simple tasks executed in order to simulate such a complex system. Therefore, it is best to ensure that these tasks are being handled promptly and in the most efficient way possible. While there are many other components of computer hardware that handle how quickly information is processed (like clock speed), it is important to understand just how revolutionary the idea of threading in computing is.