To understand more details, we need a quick way to "look into" the kernel and retrieve information; the Linux kernel's proc filesystem (often abbreviated to procfs) provides just this feature (along with more).
Here, we shall just focus on the task at hand: to get to the details, procfs exposes a directory called /proc/self (which refers to the current process's context, somewhat analogous to the this pointer in OOP); under it, a pseudo file named status reveals interesting details about the process (or ...