When CPU fetches a word from memory how does it distinct if it is word containing a data or an intruction??

Question

the main memory consists of words,which contain data and instructions...when CPU reads them jhow does it distinct if it is a data or an intruction that he reads abd fetches from memory?

Answer 1

It depends upon the program that told the CPU to fetch the item from memory: did it say, "fetch this amount and treat it as an instruction" or, "fetch this amount and treat it as data"? Further (for some computers) the information may have to be moved to certain locations in memory in order for it to be treated as instructions...and, of course, certain items of data are not valid instructions...

Answer 2

it reads the file extention. For example .exe is an instruction