What is an operating system? (cont’d)
• Abstractions:–
– Implements processes &
threads
– Implements virtual memory
& manages memory
– Provides interprocess
communication (IPC)
– Implements file system.
Manages persistent storage
of information
• Controls I/O
• Implements networking &
communications
• Definition — Same as
judicial definition of
pornography
• “I cannot define it, but I
sure can recognize one
when I see it!”