Program Fie
A executable that contains set of instructions to perform a task
It is stored as a file on the disk
Process
When the code in the program is loaded into memory and executed by the processor it is called a process
A process can need other resources (They are managed by the processor)
Each process has its own memory address space. One process cannot corrupt the memory space of another process
Thread
It is a unit of execution inside a process
Each process has at least one thread (Main Thread)
Each thread has its own stack and threads share a common address space. A misbehaving thread could cause the entire process to crash