What does it mean that more RAM is allocated than it actually is?

Question

RAM

My computer only has 8 gigabytes of RAM. In the task manager, it shows that only 17 gigabytes have been allocated. A few days ago, 15 gigabytes were allocated in general, but I noticed that when it increased to 17, the computer memory (SSD) decreased by about the same amount. I also use an integrated graphics card (if that matters).
My question is where does this allocated memory come from and is there any way to reduce this allocated memory?

Answer 1

This is the swap file. Sometimes it gets bigger, taking up more disk space. In the Manager, it shows a total of both RAM and FP, which is called virtual memory.