The Microsoft Client Server Runtime Server subsystem utilizes the process csrss.exe for managing the majority of the graphical instruction sets under the Microsoft Windows operating system. As such Csrss.exe provides the critical functions of the operating system, and its termination can result in the Blue Screen of Death being displayed.
Csrss.exe controls threading and Win32 console window features. Threading is where the application splits itself into multiple simultaneous running tasks. Threads supported by csrss.exe are different from processes in that threads are commonly contained within the process, with various threads sharing resources within the same process. The Win32 console is the plain text window in the Windows API system (programs can use the console without the need for image display).
In mobile devices such as notebooks and laptops, the process csrss.exe is closely dependent on power management schemes implemented by the system as defined under the Control Panel option.