Program, Process, and Thread:

• A program is an executable file. It is stored on the hard disk. For example, MS word software is an executable file.
• A process is an execution of a software that uses RAM. For example, creating a page on an MS word document is a process.
• A thread is a part of a process. A thread is an execution of a task within a process. A process can have multiple threads for multiple tasks. For example, On an opened page on an MS word, a thread could be to write the page. On the same page, another thread could be to check the spellings. These two threads could run in parallel within the same process of adding words in a page.