Explain the major functions of an operating system briefly. Give the difference between RISC and CISC architecture.

An OS manages resources and bridges user and hardware.

Functions: Process scheduling (multitasking OPD billing + lab prints), memory allocation + virtual memory, file management with permissions, device control via drivers/spooling, security (accounts, MFA, logs).

RISC vs CISC:

Basis	RISC	CISC
Instructions	Few, simple, fixed length	Many, complex, variable length
Execution	One per cycle, pipelined	Multi-cycle per instruction
Hardware	Simple, more registers (ARM)	Complex microcode, fewer registers (x86)
Power	Low — phones, tablets (ARM)	Higher — desktops/servers (Intel/AMD)
Example	Mobile CPU, Raspberry Pi	Office PC, hospital server

Hospital uses both: ARM tablets for rounds (battery), x86 servers for patient DB (power).