Every tutorial on OpenGL mentions that,
OpenGL codes are commands executed by the GPU.
Few days ago, my GPU cashed and I removed it from my computer. But the same OpenGL programs are still running without any additional change! What is happening?
How do you know your programs are running if you can't see anything on your screen?
Or to put it another way - you still have a GPU of some description in your computer, because in addition to executing OpenGL (or Direct3D, or Vulkan, etc) commands, your GPU is also responsible for displaying images on your screen. The fact that images are displaying on your screen (otherwise you wouldn't know if your programs were running) confirms that you have a GPU.
So what this tells me is that your computer actually had TWO GPUs, one which was most likely an Intel integrated on the motherboard, the other which was an NVIDIA or AMD and which was the one that you removed. This is quite a common configuration.