Task Type	Description
program	is a sequence of lines-of-code and/or machine-code
processes	is a program loaded into memory (i.e. in execution) processes are independent sequences of execution a process is an execution of a program processes run on separate memory spaces usually starts with a single thread i.e a primary thread but later down the line of execution it can create multiple threads
threads	threads are independent sequences of execution a thread is an execution of a program driven by the environment of a process threads run in the same memory space of its parent process
virtual thread fiber	a thread is managed and scheduled by the operating system, while a virtual thread is managed and scheduled by a virtual machine
task	either a process or thread or virtual-thread

Program vs Process

Process vs Thread vs Virtual Thread / Fiber

	Process	Heavyweight/Kernel/OS Thread	Lightweight/Virtual/User-Mode Thread - Fiber
	Process	Thread
Handled By	Operating System	Operating System	Programming Language’s Virtual Machine
Basic	program in execution	lightweight process or part of it
Memory sharing	completely isolated and do not share memory	shares memory with each other	shares memory with each other
Resource consumption	more	less	lesser
Time required for creation	more	less	lesser
Context switching time	consumes more time	consumes less time	consumes lesser time
Uncertain termination	results in loss of process	a thread can be reclaimed	?
Time required for termination	more	less	lesser