Question : What is a "service", "process", "thread"?

Hello.
What is a "service", "process" and "thread" in Windows?
Please provide as clear and distinct definitions as possible please.
Many thanks,
TC

Answer : What is a "service", "process", "thread"?

services:

http://www.omega-cottage.co.uk/articles/windows/windows-services.html
Windows Services are the programs that provide functions to applications and the Operating System. Theyre so high-priority that they get to load before anything else. In fact, theyre loaded even before you log in to Windows. Why might this be useful? Imagine youre running a Web server. Without Services, youd need to start up your PC, log in and start the server program. If, however, you have to walk away, that logged-in PC is accessible to anyone and everyone. Its much more secure to leave the system at the logon screen and allow the Web server to run in the background


What is a process?
http://www.cse.buffalo.edu/~bina/cse421/spring2007/ProcessDescAndControlJan29.ppt.
A process is simply a program in execution: an instance of a program execution.
Unit of work individually schedulable by an operating system.
OS keeps track of all the active processes and allocates system resources to them according to policies devised to meet design performance objectives.
To meet process requirements OS must maintain many data structures efficiently.
The process abstraction is a fundamental OS means for management of concurrent program execution. Example: instances of process co-existing.


What is a Process? What is a Thread? Process vs ...
http://www.cs.berkeley.edu/~istoica/classes/cs194/05/notes/4-ProcThread.pdf
A thread is an abstraction that separates the allocation of resources in a process from the execution of them.  Processes may have multiple threads inside that execute different portions of the process code.