What is the difference between a program and a process?
Interview preparation resource from Gate Smashers.
A program is a passive file containing instructions, while a process is a running instance of that program with an execution state, memory, resources and an operating-system identity.
The executable stored on disk does not have a program counter, CPU registers or allocated runtime memory. When it is launched, the OS creates a process, maps the executable into an address space and prepares the stack, heap and other runtime structures.
The same program can create many processes. Opening a browser several times may run multiple process instances from the same executable, but every process has its own identifier and protected execution state.
For example, a browser executable is a program stored on disk. When you launch it, the OS creates a process with its own PID, address space, open files and scheduling information. Launching it again can create another independent process from the same program file.